diff --git a/pkg/noun/BUILD.bazel b/pkg/noun/BUILD.bazel
index 964e4bf60f..1949a7d878 100644
--- a/pkg/noun/BUILD.bazel
+++ b/pkg/noun/BUILD.bazel
@@ -8,9 +8,8 @@ vere_library(
     name = "noun",
     srcs = glob(
         [
-            "*.c",
-            "*.h",
-            "jets/tree.c",
+            "**/*.c",
+            "**/*.h",
             "jets/*.h",
             "jets/**/*.c",
         ],
diff --git a/pkg/noun/allocate.c b/pkg/noun/allocate.c
index ace4473a4a..8ca5085397 100644
--- a/pkg/noun/allocate.c
+++ b/pkg/noun/allocate.c
@@ -16,15 +16,6 @@ u3_road* u3a_Road;
 c3_w u3_Code;
 #endif
 
-//  declarations of inline functions
-//
-
-void u3a_config_loom(c3_w ver_w);
-void *u3a_into(c3_w x);
-c3_w u3a_outa(void *p);
-c3_w u3a_to_off(c3_w som);
-void *u3a_to_ptr(c3_w som);
-c3_w *u3a_to_wtr(c3_w som);
 c3_w u3a_to_pug(c3_w off);
 c3_w u3a_to_pom(c3_w off);
 
@@ -67,37 +58,38 @@ _box_count(c3_ws siz_ws) { }
    _box_count, (others?) should have perhaps its own header and certainly its
    own prefix. having to remind yourself that _box_count doesn't actually do
    anything unless U3_CPU_DEBUG is defined is annoying. */
-#define _box_vaal(box_u)                                                \
-  do {                                                                  \
-    c3_dessert(((uintptr_t)u3a_boxto(box_u)                             \
-                & u3C.balign_d-1) == 0);                                \
-    c3_dessert((((u3a_box*)(box_u))->siz_w                              \
-                & u3C.walign_w-1) == 0);                                \
+#define _box_vaal(box_u)                                        \
+  do {                                                          \
+  c3_dessert(((uintptr_t)u3a_boxto(box_u)                       \
+              & u3a_balign-1) == 0);                            \
+  c3_dessert((((u3a_box*)(box_u))->siz_w                        \
+              & u3a_walign-1) == 0);                            \
   } while(0)
 
 /* _box_slot(): select the right free list to search for a block.
-   TODO: do we really need a loop to do this?
-
-   so our free list logic looks like this:
-   siz_w < 6 words then [0]
-   siz_w < 16      then [1]
-   siz_w < 32      then [2]
-   siz_w < 64      then [3]
-   ...
-   siz_w > 4G      then [26]
+**
+**   siz_w ==  6 words then  [0]
+**   siz_w  < 16       then  [1]
+**   siz_w  < 32       then  [2]
+**   siz_w  < 64       then  [3]
+**   ...
+**   siz_w >=  2GB     then [26]
 */
 static c3_w
 _box_slot(c3_w siz_w)
 {
-  if ( siz_w < u3a_minimum ) {
+  if ( u3a_minimum == siz_w ) {
     return 0;
   }
-
-  for (c3_w i_w = 1; i_w < u3a_fbox_no; i_w++) {
-    if ( siz_w < 16 ) return i_w;
-    siz_w = (siz_w + 1) >> 1;
+  else if ( !(siz_w >> 4) ) {
+    c3_dessert( u3a_minimum < siz_w );
+    return 1;
+  }
+  else {
+    c3_w bit_w = c3_bits_word(siz_w) - 3;
+    c3_w max_w = u3a_fbox_no - 1;
+    return c3_min(bit_w, max_w);
   }
-  return u3a_fbox_no - 1;
 }
 
 /* _box_make(): construct a box.
@@ -302,7 +294,7 @@ _ca_box_make_hat(c3_w len_w, c3_w ald_w, c3_w off_w, c3_w use_w)
     all_p += c3_wiseof(u3a_box) + off_w;
     pad_w = c3_align(all_p, ald_w, C3_ALGHI)
       - all_p;
-    siz_w = c3_align(len_w + pad_w, u3C.walign_w, C3_ALGHI);
+    siz_w = c3_align(len_w + pad_w, u3a_walign, C3_ALGHI);
 
     //  hand-inlined: siz_w >= u3a_open(u3R)
     //
@@ -316,7 +308,7 @@ _ca_box_make_hat(c3_w len_w, c3_w ald_w, c3_w off_w, c3_w use_w)
     all_p += c3_wiseof(u3a_box) + off_w;
     pad_w = all_p
       - c3_align(all_p, ald_w, C3_ALGLO);
-    siz_w = c3_align(len_w + pad_w, u3C.walign_w, C3_ALGHI);
+    siz_w = c3_align(len_w + pad_w, u3a_walign, C3_ALGHI);
 
     //  hand-inlined: siz_w >= u3a_open(u3R)
     //
@@ -508,7 +500,7 @@ _ca_willoc(c3_w len_w, c3_w ald_w, c3_w off_w)
         box_p = all_p = *pfr_p;
         all_p += c3_wiseof(u3a_box) + off_w;
         c3_w pad_w = c3_align(all_p, ald_w, C3_ALGHI) - all_p;
-        c3_w des_w = c3_align(siz_w + pad_w, u3C.walign_w, C3_ALGHI);
+        c3_w des_w = c3_align(siz_w + pad_w, u3a_walign, C3_ALGHI);
 
         /* calls maximally requesting DWORD alignment of returned pointer
            shouldn't require padding. */
@@ -711,17 +703,17 @@ u3a_wtrim(void* tox_v, c3_w old_w, c3_w len_w)
     c3_w*    box_w = (void*)u3a_botox(nov_w);
 
     c3_w* end_w = c3_align(nov_w + len_w + 1, /* +1 for trailing allocation size */
-                           u3C.balign_d,
+                           u3a_balign,
                            C3_ALGHI);
 
     c3_w  asz_w = (end_w - box_w);      /* total size in words of new allocation */
     if (box_u->siz_w <= asz_w) return;
     c3_w  bsz_w = box_u->siz_w - asz_w; /* size diff in words between old and new */
 
-    c3_dessert(asz_w && ((asz_w & u3C.walign_w-1) == 0)); /* new allocation size must be non-zero and DWORD multiple */
+    c3_dessert(asz_w && ((asz_w & u3a_walign-1) == 0)); /* new allocation size must be non-zero and DWORD multiple */
     c3_dessert(end_w < (box_w + box_u->siz_w));         /* desired alloc end must not exceed existing boundaries */
-    c3_dessert(((uintptr_t)end_w & u3C.balign_d-1) == 0); /* address of box getting freed must be DWORD aligned */
-    c3_dessert((bsz_w & u3C.walign_w-1) == 0);            /* size of box getting freed must be DWORD multiple */
+    c3_dessert(((uintptr_t)end_w & u3a_balign-1) == 0); /* address of box getting freed must be DWORD aligned */
+    c3_dessert((bsz_w & u3a_walign-1) == 0);            /* size of box getting freed must be DWORD multiple */
 
     _box_attach(_box_make(end_w, bsz_w, 0)); /* free the unneeded space */
 
@@ -1122,9 +1114,7 @@ _ca_take_atom(u3a_atom* old_u)
 static inline u3_cell
 _ca_take_cell(u3a_cell* old_u, u3_noun hed, u3_noun tel)
 {
-  //  XX use u3a_celloc?
-  //
-  c3_w*     new_w = u3a_walloc(c3_wiseof(u3a_cell));
+  c3_w*     new_w = u3a_celloc();
   u3a_cell* new_u = (u3a_cell*)(void *)new_w;
   u3_cell     new = u3a_to_pom(u3a_outa(new_u));
 
@@ -1747,24 +1737,12 @@ u3a_rewritten_noun(u3_noun som)
     return som;
   }
   u3_post som_p = u3a_rewritten(u3a_to_off(som));
-
-  /* If this is being called during a migration, one-bit pointer compression
-     needs to be temporarily enabled so the rewritten reference is compressed */
-  if (u3C.migration_state == MIG_REWRITE_COMPRESSED)
-    u3C.vits_w = 1;
-
   if ( c3y == u3a_is_pug(som) ) {
-    som_p = u3a_to_pug(som_p);
+    return u3a_to_pug(som_p);
   }
   else {
-    som_p = u3a_to_pom(som_p);
+    return u3a_to_pom(som_p);
   }
-
-  /* likewise, pointer compression is disabled until migration is complete */
-  if (u3C.migration_state == MIG_REWRITE_COMPRESSED)
-    u3C.vits_w = 0;
-
-  return som_p;
 }
 
 /* u3a_mark_mptr(): mark a malloc-allocated ptr for gc.
@@ -2152,7 +2130,8 @@ u3a_mark_road(FILE* fil_u)
   tot_w += u3a_maid(fil_u, "  profile batteries", u3a_mark_noun(u3R->pro.don));
   tot_w += u3a_maid(fil_u, "  profile doss", u3a_mark_noun(u3R->pro.day));
   tot_w += u3a_maid(fil_u, "  new profile trace", u3a_mark_noun(u3R->pro.trace));
-  tot_w += u3a_maid(fil_u, "  memoization cache", u3h_mark(u3R->cax.har_p));
+  tot_w += u3a_maid(fil_u, "  transient memoization cache", u3h_mark(u3R->cax.har_p));
+  tot_w += u3a_maid(fil_u, "  persistent memoization cache", u3h_mark(u3R->cax.per_p));
   return   u3a_maid(fil_u, "total road stuff", tot_w);
 }
 
@@ -2179,6 +2158,7 @@ u3a_rewrite_compact(void)
   u3a_rewrite_noun(u3R->pro.day);
   u3a_rewrite_noun(u3R->pro.trace);
   u3h_rewrite(u3R->cax.har_p);
+  u3h_rewrite(u3R->cax.per_p);
 
   u3R->ski.gul = u3a_rewritten_noun(u3R->ski.gul);
   u3R->bug.tax = u3a_rewritten_noun(u3R->bug.tax);
@@ -2187,6 +2167,7 @@ u3a_rewrite_compact(void)
   u3R->pro.day = u3a_rewritten_noun(u3R->pro.day);
   u3R->pro.trace = u3a_rewritten_noun(u3R->pro.trace);
   u3R->cax.har_p = u3a_rewritten(u3R->cax.har_p);
+  u3R->cax.per_p = u3a_rewritten(u3R->cax.per_p);
 }
 
 /* _ca_print_box(): heuristically print the contents of an allocation box.
@@ -2317,6 +2298,69 @@ u3a_idle(u3a_road* rod_u)
   return fre_w;
 }
 
+/* u3a_ream(): ream free-lists.
+*/
+void
+u3a_ream(void)
+{
+  u3p(u3a_fbox) lit_p;
+  u3a_fbox*     fox_u;
+  c3_w     sel_w, i_w;
+
+  for ( i_w = 0; i_w < u3a_fbox_no; i_w++ ) {
+    lit_p = u3R->all.fre_p[i_w];
+
+    while ( lit_p ) {
+      fox_u = u3to(u3a_fbox, lit_p);
+      lit_p = fox_u->nex_p;
+      sel_w = _box_slot(fox_u->box_u.siz_w);
+
+      if ( sel_w != i_w ) {
+        //  inlined _box_detach()
+        //
+        {
+          u3p(u3a_fbox) fre_p = u3of(u3a_fbox, &(fox_u->box_u));
+          u3p(u3a_fbox) pre_p = u3to(u3a_fbox, fre_p)->pre_p;
+          u3p(u3a_fbox) nex_p = u3to(u3a_fbox, fre_p)->nex_p;
+
+          if ( nex_p ) {
+            if ( u3to(u3a_fbox, nex_p)->pre_p != fre_p ) {
+              u3_assert(!"loom: corrupt");
+            }
+            u3to(u3a_fbox, nex_p)->pre_p = pre_p;
+          }
+          if ( pre_p ) {
+            if( u3to(u3a_fbox, pre_p)->nex_p != fre_p ) {
+              u3_assert(!"loom: corrupt");
+            }
+            u3to(u3a_fbox, pre_p)->nex_p = nex_p;
+          }
+          else {
+            if ( fre_p != u3R->all.fre_p[i_w] ) {
+              u3_assert(!"loom: corrupt");
+            }
+            u3R->all.fre_p[i_w] = nex_p;
+          }
+        }
+
+        //  inlined _box_attach()
+        {
+          u3p(u3a_fbox)  fre_p = u3of(u3a_fbox, &(fox_u->box_u));
+          u3p(u3a_fbox)* pfr_p = &u3R->all.fre_p[sel_w];
+          u3p(u3a_fbox)  nex_p = *pfr_p;
+
+          u3to(u3a_fbox, fre_p)->pre_p = 0;
+          u3to(u3a_fbox, fre_p)->nex_p = nex_p;
+          if ( nex_p ) {
+            u3to(u3a_fbox, nex_p)->pre_p = fre_p;
+          }
+          (*pfr_p) = fre_p;
+        }
+      }
+    }
+  }
+}
+
 /* u3a_sweep(): sweep a fully marked road.
 */
 c3_w
diff --git a/pkg/noun/allocate.h b/pkg/noun/allocate.h
index 7355954abd..b851b64c98 100644
--- a/pkg/noun/allocate.h
+++ b/pkg/noun/allocate.h
@@ -3,7 +3,6 @@
 
 #include "error.h"
 #include "manage.h"
-#include "options.h"
 
   /**  Constants.
   **/
@@ -11,14 +10,21 @@
     */
 #     define u3a_bits    U3_OS_LoomBits /* 30 */
 
-    /* u3a_vits_max: number of virtual bits in a reference gained via pointer
-       compression
+    /* u3a_vits: number of virtual bits in a noun reference gained via shifting
     */
-#     define u3a_vits_max 1
+#     define u3a_vits    1
+
+    /* u3a_walign: references into the loom are guaranteed to be word-aligned to:
+    */
+#     define u3a_walign  (1 << u3a_vits)
+
+    /* u3a_balign: u3a_walign in bytes
+    */
+#     define u3a_balign  (sizeof(c3_w)*u3a_walign)
 
      /* u3a_bits_max: max loom bex
      */
-#    define u3a_bits_max (8 * sizeof(c3_w) + u3a_vits_max)
+#    define u3a_bits_max (8 * sizeof(c3_w) + u3a_vits)
 
     /* u3a_page: number of bits in word-addressed page.  12 == 16K page
     */
@@ -26,11 +32,11 @@
 
     /* u3a_pages: maximum number of pages in memory.
     */
-#     define u3a_pages   (1ULL << (u3a_bits + u3a_vits_max - u3a_page) )
+#     define u3a_pages   (1ULL << (u3a_bits + u3a_vits - u3a_page) )
 
     /* u3a_words: maximum number of words in memory.
     */
-#     define u3a_words   ( 1ULL << (u3a_bits + u3a_vits_max ))
+#     define u3a_words   ( 1ULL << (u3a_bits + u3a_vits))
 
     /* u3a_bytes: maximum number of bytes in memory.
     */
@@ -148,11 +154,11 @@
 
         u3a_jets jed;                         //  jet dashboard
 
-        struct {                              // bytecode state
-          u3p(u3h_root) har_p;                // formula->post of bytecode
+        struct {                              //  bytecode state
+          u3p(u3h_root) har_p;                //  formula->post of bytecode
         } byc;
 
-        struct {                              //  namespace
+        struct {                              //  scry namespace
           u3_noun gul;                        //  (list $+(* (unit (unit)))) now
         } ski;
 
@@ -169,8 +175,9 @@
           u3_noun day;                        //  doss, only in u3H (moveme)
         } pro;
 
-        struct {                              //  memoization
-          u3p(u3h_root) har_p;                //  (map (pair term noun) noun)
+        struct {                              //  memoization caches
+          u3p(u3h_root) har_p;                //  transient
+          u3p(u3h_root) per_p;                //  persistent
         } cax;
       } u3a_road;
       typedef u3a_road u3_road;
@@ -226,7 +233,7 @@
     /* u3a_is_atom(): yes if noun [som] is direct atom or indirect atom.
     */
 #     define u3a_is_atom(som)    c3o(u3a_is_cat(som), \
-                                         u3a_is_pug(som))
+                                     u3a_is_pug(som))
 #     define u3ud(som)           u3a_is_atom(som)
 
     /* u3a_is_cell: yes if noun [som] is cell.
@@ -355,7 +362,7 @@
 #     define _rod_vaal(rod_u)                                           \
              do {                                                       \
                c3_dessert(((uintptr_t)((u3a_road*)(rod_u))->hat_p       \
-                           & u3C.walign_w-1) == 0);                     \
+                           & u3a_walign-1) == 0);                     \
              } while(0)
 
 
@@ -374,68 +381,40 @@
 
 #   define u3_Loom      ((c3_w *)(void *)U3_OS_LoomBase)
 
-  /**  inline functions.
-  **/
-  /* u3a_config_loom(): configure loom information by u3v version
-   */
-  inline void u3a_config_loom(c3_w ver_w) {
-    switch (ver_w) {
-    case U3V_VER1:
-      u3C.vits_w = 0;
-      break;
-    case U3V_VER2:
-      u3C.vits_w = 1;
-      break;
-    default:
-      u3_assert(0);
-    }
-
-  u3C.walign_w = 1 << u3C.vits_w;
-  u3C.balign_d = sizeof(c3_w) * u3C.walign_w;
-}
-
   /* u3a_into(): convert loom offset [x] into generic pointer.
    */
-  inline void *u3a_into(c3_w x) {
-    return u3_Loom + x;
-  }
+#   define u3a_into(x)  ((void *)(u3_Loom + (x)))
 
   /* u3a_outa(): convert pointer [p] into word offset into loom.
    */
-  inline c3_w u3a_outa(void *p) {
-    return ((c3_w *)p) - u3_Loom;
-  }
+#   define u3a_outa(p)  ((c3_w *)(void *)(p) - u3_Loom)
 
   /* u3a_to_off(): mask off bits 30 and 31 from noun [som].
    */
-  inline c3_w u3a_to_off(c3_w som) {
-    return (som & 0x3fffffff) << u3C.vits_w;
-  }
+#   define u3a_to_off(som)  (((som) & 0x3fffffff) << u3a_vits)
 
   /* u3a_to_ptr(): convert noun [som] into generic pointer into loom.
    */
-  inline void *u3a_to_ptr(c3_w som) {
-    return u3a_into(u3a_to_off(som));
-  }
+#   define u3a_to_ptr(som)  (u3a_into(u3a_to_off(som)))
 
   /* u3a_to_wtr(): convert noun [som] into word pointer into loom.
    */
-  inline c3_w *u3a_to_wtr(c3_w som) {
-    return (c3_w *)u3a_to_ptr(som);
-  }
+#   define u3a_to_wtr(som)  ((c3_w *)u3a_to_ptr(som))
 
+  /**  Inline functions.
+  **/
   /* u3a_to_pug(): set bit 31 of [off].
    */
   inline c3_w u3a_to_pug(c3_w off) {
-    c3_dessert((off & u3C.walign_w-1) == 0);
-    return (off >> u3C.vits_w) | 0x80000000;
+    c3_dessert((off & u3a_walign-1) == 0);
+    return (off >> u3a_vits) | 0x80000000;
   }
 
   /* u3a_to_pom(): set bits 30 and 31 of [off].
    */
   inline c3_w u3a_to_pom(c3_w off) {
-    c3_dessert((off & u3C.walign_w-1) == 0);
-    return (off >> u3C.vits_w) | 0xc0000000;
+    c3_dessert((off & u3a_walign-1) == 0);
+    return (off >> u3a_vits) | 0xc0000000;
   }
 
     /**  road stack.
@@ -683,6 +662,11 @@
           c3_w
           u3a_idle(u3a_road* rod_u);
 
+        /* u3a_ream(): ream free-lists.
+        */
+          void
+          u3a_ream(void);
+
         /* u3a_sweep(): sweep a fully marked road.
         */
           c3_w
diff --git a/pkg/noun/hashtable.c b/pkg/noun/hashtable.c
index 5915de5944..bc5d751b8c 100644
--- a/pkg/noun/hashtable.c
+++ b/pkg/noun/hashtable.c
@@ -1017,15 +1017,8 @@ _ch_rewrite_node(u3h_node* han_u, c3_w lef_w)
     else {
       void* hav_v = u3h_slot_to_node(sot_w);
       u3h_node* nod_u = u3to(u3h_node,u3a_rewritten(u3of(u3h_node,hav_v)));
-
-      if (u3C.migration_state == MIG_REWRITE_COMPRESSED)
-        u3C.vits_w = 1;
-
       han_u->sot_w[i_w] = u3h_node_to_slot(nod_u);
 
-      if (u3C.migration_state == MIG_REWRITE_COMPRESSED)
-        u3C.vits_w = 0;
-
       if ( 0 == lef_w ) {
         _ch_rewrite_buck(hav_v);
       } else {
@@ -1057,15 +1050,8 @@ u3h_rewrite(u3p(u3h_root) har_p)
     else if ( _(u3h_slot_is_node(sot_w)) ) {
       u3h_node* han_u = u3h_slot_to_node(sot_w);
       u3h_node* nod_u = u3to(u3h_node,u3a_rewritten(u3of(u3h_node,han_u)));
-
-      if (u3C.migration_state == MIG_REWRITE_COMPRESSED)
-        u3C.vits_w = 1;
-
       har_u->sot_w[i_w] = u3h_node_to_slot(nod_u);
 
-      if (u3C.migration_state == MIG_REWRITE_COMPRESSED)
-        u3C.vits_w = 0;
-
       _ch_rewrite_node(han_u, 25);
     }
   }
diff --git a/pkg/noun/hashtable.h b/pkg/noun/hashtable.h
index be1d3f93be..291ef28a0c 100644
--- a/pkg/noun/hashtable.h
+++ b/pkg/noun/hashtable.h
@@ -16,9 +16,8 @@
     ***  corresponding to the 32-slot nodes for everything under
     ***  the root node.
     ***
-    ***  We store an extra "freshly warm" bit for a simple
-    ***  clock-algorithm reclamation policy, not yet implemented.
-    ***  Search "clock algorithm" to figure it out.
+    ***  We store an extra "freshly warm" bit and use it for a simple
+    ***  clock-algorithm reclamation policy.
     **/
       /* u3h_slot: map slot.
       **
@@ -79,8 +78,8 @@
 #     define  u3h_slot_is_node(sot)  ((1 == ((sot) >> 30)) ? c3y : c3n)
 #     define  u3h_slot_is_noun(sot)  ((1 == ((sot) >> 31)) ? c3y : c3n)
 #     define  u3h_slot_is_warm(sot)  (((sot) & 0x40000000) ? c3y : c3n)
-#     define  u3h_slot_to_node(sot)  (u3a_into(((sot) & 0x3fffffff) << u3C.vits_w))
-#     define  u3h_node_to_slot(ptr)  ((u3a_outa((ptr)) >> u3C.vits_w) | 0x40000000)
+#     define  u3h_slot_to_node(sot)  (u3a_into(((sot) & 0x3fffffff) << u3a_vits))
+#     define  u3h_node_to_slot(ptr)  ((u3a_outa((ptr)) >> u3a_vits) | 0x40000000)
 #     define  u3h_noun_be_warm(sot)  ((sot) | 0x40000000)
 #     define  u3h_noun_be_cold(sot)  ((sot) & ~0x40000000)
 #     define  u3h_slot_to_noun(sot)  (0x40000000 | (sot))
diff --git a/pkg/noun/jets.c b/pkg/noun/jets.c
index 00edefec40..13e417dab6 100644
--- a/pkg/noun/jets.c
+++ b/pkg/noun/jets.c
@@ -18,15 +18,6 @@
 #include "vortex.h"
 #include "xtract.h"
 
-/**  Data structures.
-**/
-
-/* _cj_hank: cached hook information.
- */
-typedef struct {
-  u3_weak  hax;                     //  axis of hooked inner core
-  u3j_site sit_u;                   //  call-site data
-} _cj_hank;
 
 /**  Functions.
 **/
@@ -1069,7 +1060,7 @@ _cj_prog(u3_weak loc, u3_noun fol)
 /* cj_hank_find(): find cached hook information, keyed by arbitrary
  *                 prefix and term cords. RETAIN.
  */
-static _cj_hank*
+static u3j_hank*
 _cj_hank_find(u3_noun pre, u3_noun tam)
 {
   u3_noun key = u3nc(u3k(pre), u3k(tam));
@@ -1077,10 +1068,10 @@ _cj_hank_find(u3_noun pre, u3_noun tam)
 
   if ( u3_none != got ) {
     u3z(key);
-    return u3to(_cj_hank, got);
+    return u3to(u3j_hank, got);
   }
   else {
-    _cj_hank* new_u = u3a_walloc(c3_wiseof(_cj_hank));
+    u3j_hank* new_u = u3a_walloc(c3_wiseof(u3j_hank));
     u3a_road* rod_u = u3R;
 
     while ( rod_u->par_p && u3_none == got ) {
@@ -1092,7 +1083,7 @@ _cj_hank_find(u3_noun pre, u3_noun tam)
       new_u->hax = u3_none;
     }
     else {
-      _cj_hank* old_u = u3to(_cj_hank, got);
+      u3j_hank* old_u = u3to(u3j_hank, got);
       if ( u3_none != (new_u->hax = old_u->hax) ) {
         //  it's unusual but safe to "take" here, because
         //  u3a_take will no-op on senior nouns (just as u3k would)
@@ -1101,7 +1092,7 @@ _cj_hank_find(u3_noun pre, u3_noun tam)
       }
     }
 
-    u3h_put(u3R->jed.han_p, key, u3of(_cj_hank, new_u));
+    u3h_put(u3R->jed.han_p, key, u3of(u3j_hank, new_u));
     u3z(key);
     return new_u;
   }
@@ -1112,7 +1103,7 @@ _cj_hank_find(u3_noun pre, u3_noun tam)
  *                  core on return if valid. RETAIN.
  */
 static c3_o
-_cj_hank_fine(_cj_hank* han_u, u3_noun cor, u3_noun *inn)
+_cj_hank_fine(u3j_hank* han_u, u3_noun cor, u3_noun *inn)
 {
   u3_noun hax = han_u->hax;
   if ( u3_none == hax ) {
@@ -1134,7 +1125,7 @@ _cj_hank_fine(_cj_hank* han_u, u3_noun cor, u3_noun *inn)
 /* _cj_hank_lose(): release memory maintained in a hook cache.
 */
 static void
-_cj_hank_lose(_cj_hank* han_u)
+_cj_hank_lose(u3j_hank* han_u)
 {
   if ( u3_none != han_u->hax ) {
     u3z(han_u->hax);
@@ -1145,7 +1136,7 @@ _cj_hank_lose(_cj_hank* han_u)
 /* _cj_hank_fill(): slow path, populate han_u.
  */
 static u3_noun
-_cj_hank_fill(_cj_hank* han_u, u3_noun tam, u3_noun cor)
+_cj_hank_fill(u3j_hank* han_u, u3_noun tam, u3_noun cor)
 {
   u3_weak   loc, col;
   u3_noun   got, pat, nam, huc;
@@ -1642,7 +1633,7 @@ u3j_cook(const c3_c* key_c,
          const c3_c* tam_c)
 {
   u3_noun pro, key, tam, inn;
-  _cj_hank* han_u;
+  u3j_hank* han_u;
 
   u3t_on(glu_o);
   key = u3i_string(key_c);
@@ -1992,11 +1983,11 @@ u3j_rite_mine(u3j_rite* rit_u, u3_noun clu, u3_noun cor)
 
 /* _cj_take_hank_cb(): u3h_take_with cb for taking hanks
 */
-static u3p(_cj_hank)
-_cj_take_hank_cb(u3p(_cj_hank) nah_p)
+static u3p(u3j_hank)
+_cj_take_hank_cb(u3p(u3j_hank) nah_p)
 {
-  _cj_hank* nah_u = u3to(_cj_hank, nah_p);
-  _cj_hank* han_u = u3a_walloc(c3_wiseof(_cj_hank));
+  u3j_hank* nah_u = u3to(u3j_hank, nah_p);
+  u3j_hank* han_u = u3a_walloc(c3_wiseof(u3j_hank));
 
   if ( u3_none == nah_u->hax ) {
     han_u->hax = u3_none;
@@ -2007,7 +1998,7 @@ _cj_take_hank_cb(u3p(_cj_hank) nah_p)
     u3j_site_take(&(han_u->sit_u), &(nah_u->sit_u));
   }
 
-  return u3of(_cj_hank, han_u);
+  return u3of(u3j_hank, han_u);
 }
 
 /* u3j_take(): copy junior jet state.
@@ -2029,25 +2020,25 @@ static void
 _cj_merge_hank_cb(u3_noun kev, void* wit)
 {
   u3p(u3h_root) han_p = *(u3p(u3h_root)*)wit;
-  _cj_hank* nah_u;
+  u3j_hank* nah_u;
   u3_noun key;
-  u3p(_cj_hank) nah_p;
+  u3p(u3j_hank) nah_p;
   u3x_cell(kev, &key, &nah_p);
 
-  nah_u = u3to(_cj_hank, nah_p);
+  nah_u = u3to(u3j_hank, nah_p);
 
   if ( u3_none == nah_u->hax ) {
     u3a_wfree(nah_u);
   }
   else {
-    _cj_hank* han_u;
+    u3j_hank* han_u;
     u3_weak     got = u3h_git(u3R->jed.han_p, key);
 
     if ( u3_none == got )  {
       han_u = nah_u;
     }
     else {
-      han_u = u3to(_cj_hank, got);
+      han_u = u3to(u3j_hank, got);
 
       if ( u3_none != han_u->hax ) {
         u3z(han_u->hax);
@@ -2058,7 +2049,7 @@ _cj_merge_hank_cb(u3_noun kev, void* wit)
       u3a_wfree(nah_u);
     }
 
-    u3h_put(han_p, key, u3of(_cj_hank, han_u));
+    u3h_put(han_p, key, u3of(u3j_hank, han_u));
   }
 }
 
@@ -2170,7 +2161,7 @@ _cj_warm_tap(u3_noun kev, void* wit)
 static void
 _cj_ream_hank(u3_noun kev)
 {
-  u3j_site_ream(&(u3to(_cj_hank, u3t(kev))->sit_u));
+  u3j_site_ream(&(u3to(u3j_hank, u3t(kev))->sit_u));
 }
 
 /* u3j_ream(): rebuild warm state
@@ -2304,7 +2295,7 @@ static void
 _cj_mark_hank(u3_noun kev, void* dat)
 {
   c3_w* tot_w = (c3_w*) dat;
-  _cj_hank* han_u = u3to(_cj_hank, u3t(kev));
+  u3j_hank* han_u = u3to(u3j_hank, u3t(kev));
   *tot_w += u3a_mark_ptr(han_u);
   if ( u3_none != han_u->hax ) {
     *tot_w += u3a_mark_noun(han_u->hax);
@@ -2337,12 +2328,12 @@ u3j_mark(FILE* fil_u)
   return u3a_maid(fil_u, "total jet stuff", tot_w);
 }
 
-/* _cj_free_hank(): free an entry from the hank cache.
+/* u3j_free_hank(): free an entry from the hank cache.
 */
-static void
-_cj_free_hank(u3_noun kev)
+void
+u3j_free_hank(u3_noun kev)
 {
-  _cj_hank* han_u = u3to(_cj_hank, u3t(kev));
+  u3j_hank* han_u = u3to(u3j_hank, u3t(kev));
   if ( u3_none != han_u->hax ) {
     u3z(han_u->hax);
     u3j_site_lose(&(han_u->sit_u));
@@ -2355,7 +2346,7 @@ _cj_free_hank(u3_noun kev)
 void
 u3j_free(void)
 {
-  u3h_walk(u3R->jed.han_p, _cj_free_hank);
+  u3h_walk(u3R->jed.han_p, u3j_free_hank);
   u3h_free(u3R->jed.war_p);
   u3h_free(u3R->jed.cod_p);
   u3h_free(u3R->jed.han_p);
@@ -2377,10 +2368,9 @@ u3j_reclaim(void)
   // if ( &(u3H->rod_u) == u3R ) {
   //   u3j_ream();
   // }
-
   //  clear the jet hank cache
   //
-  u3h_walk(u3R->jed.han_p, _cj_free_hank);
+  u3h_walk(u3R->jed.han_p, u3j_free_hank);
   u3h_free(u3R->jed.han_p);
   u3R->jed.han_p = u3h_new();
 }
diff --git a/pkg/noun/jets.h b/pkg/noun/jets.h
index 9c5241c5db..1440f7558a 100644
--- a/pkg/noun/jets.h
+++ b/pkg/noun/jets.h
@@ -126,6 +126,13 @@
         u3p(u3j_fink) fin_p;          //  fine check
       } u3j_site;
 
+      /* u3j_hank: cached hook information.
+       */
+      typedef struct {
+        u3_weak  hax;                     //  axis of hooked inner core
+        u3j_site sit_u;                   //  call-site data
+      } u3j_hank;
+
   /** Globals.
   **/
     /* u3_Dash: jet dashboard.
@@ -297,6 +304,11 @@
         void
         u3j_free(void);
 
+      /* u3j_free_hank(): free an entry from the hank cache.
+      */
+        void
+        u3j_free_hank(u3_noun kev);
+
       /* u3j_reclaim(): clear ad-hoc persistent caches to reclaim memory.
       */
         void
diff --git a/pkg/noun/jets/f/ut_crop.c b/pkg/noun/jets/f/ut_crop.c
index 1969a13a3d..189564d0c3 100644
--- a/pkg/noun/jets/f/ut_crop.c
+++ b/pkg/noun/jets/f/ut_crop.c
@@ -20,7 +20,7 @@ u3wfu_crop(u3_noun cor)
     u3_weak vet = u3r_at(u3qfu_van_vet, van);
     c3_m  fun_m = 141 + c3__crop + ((!!vet) << 8);
     u3_noun key = u3z_key_3(fun_m, sut, ref, bat);
-    u3_weak pro = u3z_find(key);
+    u3_weak pro = u3z_find(u3z_memo_toss, key);
 
     if ( u3_none != pro ) {
       u3z(key);
@@ -28,7 +28,7 @@ u3wfu_crop(u3_noun cor)
     }
     else {
       pro = u3n_nock_on(u3k(cor), u3k(u3x_at(u3x_bat, cor)));
-      return u3z_save(key, pro);
+      return u3z_save(u3z_memo_toss, key, pro);
     }
   }
 }
diff --git a/pkg/noun/jets/f/ut_fish.c b/pkg/noun/jets/f/ut_fish.c
index e7505b9345..e8acbd43cf 100644
--- a/pkg/noun/jets/f/ut_fish.c
+++ b/pkg/noun/jets/f/ut_fish.c
@@ -21,7 +21,7 @@ u3wfu_fish(u3_noun cor)
     u3_weak vet = u3r_at(u3qfu_van_vet, van);
     c3_m  fun_m = 141 + c3__fish + ((!!vet) << 8);
     u3_noun key = u3z_key_3(fun_m, sut, axe, bat);
-    u3_weak pro = u3z_find(key);
+    u3_weak pro = u3z_find(u3z_memo_toss, key);
 
     if ( u3_none != pro ) {
       u3z(key);
@@ -29,7 +29,7 @@ u3wfu_fish(u3_noun cor)
     }
     else {
       pro = u3n_nock_on(u3k(cor), u3k(u3x_at(u3x_bat, cor)));
-      return u3z_save(key, pro);
+      return u3z_save(u3z_memo_toss, key, pro);
     }
   }
 }
diff --git a/pkg/noun/jets/f/ut_fuse.c b/pkg/noun/jets/f/ut_fuse.c
index f9fac33a4d..8e4e1a6135 100644
--- a/pkg/noun/jets/f/ut_fuse.c
+++ b/pkg/noun/jets/f/ut_fuse.c
@@ -20,7 +20,7 @@ u3wfu_fuse(u3_noun cor)
     u3_weak vet = u3r_at(u3qfu_van_vet, van);
     c3_m  fun_m = 141 + c3__fuse + ((!!vet) << 8);
     u3_noun key = u3z_key_3(fun_m, sut, ref, bat);
-    u3_weak pro = u3z_find(key);
+    u3_weak pro = u3z_find(u3z_memo_toss, key);
 
     if ( u3_none != pro ) {
       u3z(key);
@@ -28,7 +28,7 @@ u3wfu_fuse(u3_noun cor)
     }
     else {
       pro = u3n_nock_on(u3k(cor), u3k(u3x_at(u3x_bat, cor)));
-      return u3z_save(key, pro);
+      return u3z_save(u3z_memo_toss, key, pro);
     }
   }
 }
diff --git a/pkg/noun/jets/f/ut_mint.c b/pkg/noun/jets/f/ut_mint.c
index fc8424854a..618e7291fd 100644
--- a/pkg/noun/jets/f/ut_mint.c
+++ b/pkg/noun/jets/f/ut_mint.c
@@ -22,7 +22,7 @@ u3wfu_mint(u3_noun cor)
     c3_m  fun_m = 141 + c3__mint;
     u3_noun vet = u3r_at(u3qfu_van_vet, van);
     u3_noun key = u3z_key_5(fun_m, vet, sut, gol, gen, bat);
-    u3_weak pro = u3z_find(key);
+    u3_weak pro = u3z_find(u3z_memo_toss, key);
 
     if ( u3_none != pro ) {
       u3z(key);
@@ -30,7 +30,7 @@ u3wfu_mint(u3_noun cor)
     }
     else {
       pro = u3n_nock_on(u3k(cor), u3k(u3x_at(u3x_bat, cor)));
-      return u3z_save(key, pro);
+      return u3z_save(u3z_memo_toss, key, pro);
     }
   }
 }
diff --git a/pkg/noun/jets/f/ut_mull.c b/pkg/noun/jets/f/ut_mull.c
index 98e62ca57e..767ab3c51a 100644
--- a/pkg/noun/jets/f/ut_mull.c
+++ b/pkg/noun/jets/f/ut_mull.c
@@ -23,7 +23,7 @@ u3wfu_mull(u3_noun cor)
     u3_weak vet = u3r_at(u3qfu_van_vet, van);
     c3_m  fun_m = 141 + c3__mull + ((!!vet) << 8);
     u3_noun key = u3z_key_5(fun_m, sut, gol, dox, gen, bat);
-    u3_weak pro = u3z_find(key);
+    u3_weak pro = u3z_find(u3z_memo_toss, key);
 
     if ( u3_none != pro ) {
       u3z(key);
@@ -31,7 +31,7 @@ u3wfu_mull(u3_noun cor)
     }
     else {
       pro = u3n_nock_on(u3k(cor), u3k(u3x_at(u3x_bat, cor)));
-      return u3z_save(key, pro);
+      return u3z_save(u3z_memo_toss, key, pro);
     }
   }
 }
diff --git a/pkg/noun/jets/f/ut_nest.c b/pkg/noun/jets/f/ut_nest.c
index 765081a5cb..9bc53bf0f9 100644
--- a/pkg/noun/jets/f/ut_nest.c
+++ b/pkg/noun/jets/f/ut_nest.c
@@ -27,7 +27,7 @@ u3wfu_nest_dext(u3_noun dext_core)
     u3_weak vet = u3r_at(u3qfu_van_vet, van);
     c3_m  fun_m = 141 + c3__dext + ((!!vet) << 8);
     u3_noun key = u3z_key_3(fun_m, sut, ref, bat);
-    u3_weak pro = u3z_find(key);
+    u3_weak pro = u3z_find(u3z_memo_toss, key);
 
     if ( u3_none != pro ) {
       u3z(key);
@@ -39,7 +39,7 @@ u3wfu_nest_dext(u3_noun dext_core)
       if ( ((c3y == pro) && (u3_nul == reg)) ||
            ((c3n == pro) && (u3_nul == seg)) )
       {
-        return u3z_save(key, pro);
+        return u3z_save(u3z_memo_toss, key, pro);
       }
       else {
         u3z(key);
diff --git a/pkg/noun/jets/f/ut_rest.c b/pkg/noun/jets/f/ut_rest.c
index 3fdbed23b0..87ff60fa68 100644
--- a/pkg/noun/jets/f/ut_rest.c
+++ b/pkg/noun/jets/f/ut_rest.c
@@ -20,7 +20,7 @@ u3wfu_rest(u3_noun cor)
     u3_weak vet = u3r_at(u3qfu_van_vet, van);
     c3_m  fun_m = 141 + c3__rest + ((!!vet) << 8);
     u3_noun key = u3z_key_3(fun_m, sut, leg, bat);
-    u3_weak pro = u3z_find(key);
+    u3_weak pro = u3z_find(u3z_memo_toss, key);
 
     if ( u3_none != pro ) {
       u3z(key);
@@ -28,7 +28,7 @@ u3wfu_rest(u3_noun cor)
     }
     else {
       pro = u3n_nock_on(u3k(cor), u3k(u3x_at(u3x_bat, cor)));
-      return u3z_save(key, pro);
+      return u3z_save(u3z_memo_toss, key, pro);
     }
   }
 }
diff --git a/pkg/noun/manage.c b/pkg/noun/manage.c
index 9b6d47fcab..2de555d58c 100644
--- a/pkg/noun/manage.c
+++ b/pkg/noun/manage.c
@@ -1,6 +1,8 @@
 /// @file
 
-#include "manage.h"
+#include "pkg/noun/manage.h"
+#include "pkg/noun/v2/manage.h"
+#include "pkg/noun/v3/manage.h"
 
 #include <ctype.h>
 #include <errno.h>
@@ -473,9 +475,8 @@ u3m_mark(FILE* fil_u)
 static void
 _pave_parts(void)
 {
-  // TODO: pass `u3_Host.ops_u.hap_w` into `noun` library as an argument and use
-  // as size of memo cache.
-  u3R->cax.har_p = u3h_new_cache(50000);
+  u3R->cax.har_p = u3h_new_cache(u3C.hap_w);  //  transient
+  u3R->cax.per_p = u3h_new_cache(u3C.per_w);  //  persistent
   u3R->jed.war_p = u3h_new();
   u3R->jed.cod_p = u3h_new();
   u3R->jed.han_p = u3h_new();
@@ -488,7 +489,7 @@ _pave_parts(void)
 static u3_road*
 _pave_road(c3_w* rut_w, c3_w* mat_w, c3_w* cap_w, c3_w siz_w)
 {
-  c3_dessert(((uintptr_t)rut_w & u3C.balign_d-1) == 0);
+  c3_dessert(((uintptr_t)rut_w & u3a_balign-1) == 0);
   u3_road* rod_u = (void*) mat_w;
 
   //  enable in case of corruption
@@ -529,8 +530,8 @@ _pave_north(c3_w* mem_w, c3_w siz_w, c3_w len_w, c3_o kid_o)
   //    00~~~|R|---|H|######|C|+++|M|~~~FF
   //                                ^--u3R which _pave_road returns (u3H for home road)
   //
-  c3_w* mat_w = c3_align(mem_w + len_w - siz_w, u3C.balign_d, C3_ALGLO);
-  c3_w* rut_w = c3_align(mem_w, u3C.balign_d, C3_ALGHI);
+  c3_w* mat_w = c3_align(mem_w + len_w - siz_w, u3a_balign, C3_ALGLO);
+  c3_w* rut_w = c3_align(mem_w, u3a_balign, C3_ALGHI);
   c3_w* cap_w = mat_w;
 
   if ( c3y == kid_o ) {
@@ -560,8 +561,8 @@ _pave_south(c3_w* mem_w, c3_w siz_w, c3_w len_w)
   //    00~~~|M|+++|C|######|H|---|R|~~~FFF
   //         ^---u3R which _pave_road returns
   //
-  c3_w* mat_w = c3_align(mem_w, u3C.balign_d, C3_ALGHI);
-  c3_w* rut_w = c3_align(mem_w + len_w, u3C.balign_d, C3_ALGLO);
+  c3_w* mat_w = c3_align(mem_w, u3a_balign, C3_ALGHI);
+  c3_w* rut_w = c3_align(mem_w + len_w, u3a_balign, C3_ALGLO);
   c3_w* cap_w = mat_w + siz_w;
 
   u3e_ward(u3of(c3_w, cap_w) - 1, u3of(c3_w, rut_w));
@@ -574,12 +575,9 @@ _pave_south(c3_w* mem_w, c3_w siz_w, c3_w len_w)
 static void
 _pave_home(void)
 {
-  /* a pristine home road will always have compressed references */
-  u3a_config_loom(U3V_VERLAT);
-
-  c3_w* mem_w = u3_Loom + u3C.walign_w;
+  c3_w* mem_w = u3_Loom + u3a_walign;
   c3_w  siz_w = c3_wiseof(u3v_home);
-  c3_w  len_w = u3C.wor_i - u3C.walign_w;
+  c3_w  len_w = u3C.wor_i - u3a_walign;
 
   u3H = (void *)_pave_north(mem_w, siz_w, len_w, c3n);
   u3H->ver_w = U3V_VERLAT;
@@ -597,14 +595,29 @@ static void
 _find_home(void)
 {
   c3_w ver_w = *(u3_Loom + u3C.wor_i - 1);
-  u3a_config_loom(ver_w);
+  c3_o mig_o = c3y;  //  did we migrate?
+
+  switch ( ver_w ) {
+    case U3V_VER1: u3m_v2_migrate();
+    case U3V_VER2: u3m_v3_migrate();
+    case U3V_VER3: {
+      mig_o = c3n;
+      break;
+    }
+    default: {
+      fprintf(stderr, "loom: checkpoint version mismatch: "
+                      "have %u, need %u\r\n",
+                      ver_w, U3V_VERLAT);
+      abort();
+    }
+  }
 
   //  NB: the home road is always north
   //
-  c3_w* mem_w = u3_Loom + u3C.walign_w;
+  c3_w* mem_w = u3_Loom + u3a_walign;
   c3_w  siz_w = c3_wiseof(u3v_home);
-  c3_w  len_w = u3C.wor_i - u3C.walign_w;
-  c3_w* mat_w = c3_align(mem_w + len_w - siz_w, u3C.balign_d, C3_ALGLO);
+  c3_w  len_w = u3C.wor_i - u3a_walign;
+  c3_w* mat_w = c3_align(mem_w + len_w - siz_w, u3a_balign, C3_ALGLO);
 
   u3H = (void *)mat_w;
   u3R = &u3H->rod_u;
@@ -616,7 +629,7 @@ _find_home(void)
 
   //  check for obvious corruption
   //
-  {
+  if ( c3n == mig_o ) {
     c3_w    nor_w, sou_w;
     u3_post low_p, hig_p;
     u3m_water(&low_p, &hig_p);
@@ -642,18 +655,6 @@ _find_home(void)
   /* As a further guard against any sneaky loom corruption */
   u3a_loom_sane();
 
-  if (U3V_VERLAT > ver_w) {
-    u3m_migrate(U3V_VERLAT);
-    u3a_config_loom(U3V_VERLAT);
-  }
-  else if ( U3V_VERLAT < ver_w ) {
-    fprintf(stderr, "loom: checkpoint version mismatch: "
-            "have %u, need %u\r\n",
-            ver_w,
-            U3V_VERLAT);
-    abort();
-  }
-
   _rod_vaal(u3R);
 }
 
@@ -748,13 +749,6 @@ u3m_dump(void)
 c3_i
 u3m_bail(u3_noun how)
 {
-  if ( &(u3H->rod_u) == u3R ) {
-    //  XX set exit code
-    //
-    fprintf(stderr, "home: bailing out\r\n");
-    abort();
-  }
-
   //  printf some metadata
   //
   switch ( how ) {
@@ -779,6 +773,13 @@ u3m_bail(u3_noun how)
     }
   }
 
+  if ( &(u3H->rod_u) == u3R ) {
+    //  XX set exit code
+    //
+    fprintf(stderr, "home: bailing out\r\n");
+    abort();
+  }
+
   //  intercept fatal errors
   //
   switch ( how ) {
@@ -865,7 +866,7 @@ u3m_leap(c3_w pad_w)
     }
     pad_w += c3_wiseof(u3a_road);
     len_w = u3a_open(u3R) - pad_w;
-    c3_align(len_w, u3C.walign_w, C3_ALGHI);
+    c3_align(len_w, u3a_walign, C3_ALGHI);
   }
 
   /* Allocate a region on the cap.
@@ -996,6 +997,7 @@ u3m_love(u3_noun pro)
   //
   u3p(u3h_root) byc_p = u3R->byc.har_p;
   u3a_jets      jed_u = u3R->jed;
+  u3p(u3h_root) per_p = u3R->cax.per_p;
 
   //  fallback to parent road (child heap on parent's stack)
   //
@@ -1006,6 +1008,7 @@ u3m_love(u3_noun pro)
   pro   = u3a_take(pro);
   jed_u = u3j_take(jed_u);
   byc_p = u3n_take(byc_p);
+  per_p = u3h_take(per_p);
 
   //  pop the stack
   //
@@ -1016,6 +1019,7 @@ u3m_love(u3_noun pro)
   //
   u3j_reap(jed_u);
   u3n_reap(byc_p);
+  u3z_reap(u3z_memo_keep, per_p);
 
   return pro;
 }
@@ -2202,7 +2206,7 @@ u3m_boot_lite(size_t len_i)
   return 0;
 }
 
-/* u3m_reclaim: clear persistent caches to reclaim memory
+/* u3m_reclaim: clear persistent caches to reclaim memory.
 */
 void
 u3m_reclaim(void)
@@ -2218,7 +2222,7 @@ u3m_reclaim(void)
 static void
 _cm_pack_rewrite(void)
 {
-  //  XX fix u3a_rewrit* to support south roads
+  //  XX fix u3a_rewrite* to support south roads
   //
   u3_assert( &(u3H->rod_u) == u3R );
 
@@ -2256,158 +2260,3 @@ u3m_pack(void)
 
   return (u3a_open(u3R) - pre_w);
 }
-
-static void
-_migrate_reclaim()
-{
-  fprintf(stderr, "loom: migration reclaim\r\n");
-  u3m_reclaim();
-}
-
-static void
-_migrate_seek(const u3a_road *rod_u)
-{
-  /*
-    very much like u3a_pack_seek with the following changes:
-    - there is no need to account for free space as |pack is performed before
-      the migration
-    - odd sized boxes will be padded by one word to achieve an even size
-    - rut will be moved from one word ahead of u3_Loom to two words ahead
-  */
-  c3_w *    box_w = u3a_into(rod_u->rut_p);
-  c3_w *    end_w = u3a_into(rod_u->hat_p);
-  u3_post   new_p = (rod_u->rut_p + 1 + c3_wiseof(u3a_box));
-  u3a_box * box_u = (void *)box_w;
-
-  fprintf(stderr, "loom: migration seek\r\n");
-
-  for (; box_w < end_w
-         ; box_w += box_u->siz_w
-         , box_u = (void*)box_w)
-    {
-      if (!box_u->use_w)
-        continue;
-      u3_assert(box_u->siz_w);
-      u3_assert(box_u->use_w);
-      box_w[box_u->siz_w - 1] = new_p;
-      new_p = c3_align(new_p + box_u->siz_w, 2, C3_ALGHI);
-    }
-}
-
-static void
-_migrate_rewrite()
-{
-  fprintf(stderr, "loom: migration rewrite\r\n");
-
-  /* So that rewritten pointers are compressed, this flag is set */
-  u3C.migration_state = MIG_REWRITE_COMPRESSED;
-  _cm_pack_rewrite();
-  u3C.migration_state = MIG_NONE;
-}
-
-static void
-_migrate_move(u3a_road *rod_u)
-{
-  fprintf(stderr, "loom: migration move\r\n");
-
-  c3_z hiz_z = u3a_heap(rod_u) * sizeof(c3_w);
-
-  /* calculate required shift distance to prevent write head overlapping read head */
-  c3_w  off_w = 1;  /* at least 1 word because u3R->rut_p migrates from 1 to 2 */
-  for (u3a_box *box_u = u3a_into(rod_u->rut_p)
-         ; (void *)box_u < u3a_into(rod_u->hat_p)
-         ; box_u = (void *)((c3_w *)box_u + box_u->siz_w))
-    off_w += box_u->siz_w & 1; /* odd-sized boxes are padded by one word */
-
-  /* shift */
-  memmove(u3a_into(u3H->rod_u.rut_p + off_w),
-          u3a_into(u3H->rod_u.rut_p),
-          hiz_z);
-  /* manually zero the former rut */
-  *(c3_w *)u3a_into(rod_u->rut_p) = 0;
-
-  /* relocate boxes to DWORD-aligned addresses stored in trailing size word */
-  c3_w *box_w = u3a_into(rod_u->rut_p + off_w);
-  c3_w *end_w = u3a_into(rod_u->hat_p + off_w);
-  u3a_box *old_u = (void *)box_w;
-  c3_w siz_w = old_u->siz_w;
-  u3p(c3_w) new_p = rod_u->rut_p + 1 + c3_wiseof(u3a_box);
-  c3_w *new_w;
-
-  for (; box_w < end_w
-         ; box_w += siz_w
-         , old_u = (void *)box_w
-         , siz_w = old_u->siz_w) {
-    old_u->use_w &= 0x7fffffff;
-
-    if (!old_u->use_w)
-      continue;
-
-    new_w = (void *)u3a_botox(u3a_into(new_p));
-    u3_assert(box_w[siz_w - 1] == new_p);
-    u3_assert(new_w <= box_w);
-
-    c3_w i_w;
-    for (i_w = 0; i_w < siz_w - 1; i_w++)
-      new_w[i_w] = box_w[i_w];
-
-    if (siz_w & 1) {
-      new_w[i_w++] = 0;         /* pad odd sized boxes */
-      new_w[i_w++] = siz_w + 1; /* restore trailing size word */
-      new_w[0] = siz_w + 1;     /* and the leading size word */
-    }
-    else {
-      new_w[i_w++] = siz_w;
-    }
-
-    new_p += i_w;
-  }
-
-  /* restore proper heap state */
-  rod_u->rut_p = 2;
-  rod_u->hat_p = new_p - c3_wiseof(u3a_box);
-
-  /* like |pack, clear the free lists and cell allocator */
-  for (c3_w i_w = 0; i_w < u3a_fbox_no; i_w++)
-    u3R->all.fre_p[i_w] = 0;
-
-  u3R->all.fre_w = 0;
-  u3R->all.cel_p = 0;
-}
-
-
-/* u3m_migrate: perform loom migration if necessary.
-   ver_w - target version
-*/
-void
-u3m_migrate(u3v_version ver_w)
-{
-  if (u3H->ver_w == ver_w)
-    return;
-
-  /* 1 -> 2 is all that is currently supported */
-  c3_dessert(u3H->ver_w == U3V_VER1 &&
-             ver_w == U3V_VER2);
-
-  /* only home road migration is supported */
-  c3_dessert((uintptr_t)u3H == (uintptr_t)u3R);
-
-  fprintf(stderr, "loom: migration running. This may take several minutes to perform.\r\n");
-  fprintf(stderr, "loom: have version: %"PRIc3_w" migrating to version: %"PRIc3_w"\r\n",
-          u3H->ver_w, ver_w);
-
-  /* packing first simplifies migration logic and minimizes required buffer space */
-  u3m_pack();
-
-  /* perform the migration in a pattern similar to |pack */
-  _migrate_reclaim();
-  _migrate_seek(&u3H->rod_u);
-  _migrate_rewrite();
-  _migrate_move(&u3H->rod_u);
-
-  /* finally update the version and commit to disk */
-  u3H->ver_w = ver_w;
-  /* extra assurance we haven't corrupted the loom before writing to disk */
-  u3a_loom_sane();
-  u3m_save();
-}
diff --git a/pkg/noun/manage.h b/pkg/noun/manage.h
index 56d4ca7901..14f9cc503d 100644
--- a/pkg/noun/manage.h
+++ b/pkg/noun/manage.h
@@ -3,6 +3,9 @@
 #ifndef U3_MANAGE_H
 #define U3_MANAGE_H
 
+#include "v1/manage.h"
+#include "v2/manage.h"
+
 #include "c3.h"
 #include "types.h"
 #include "version.h"
@@ -185,7 +188,7 @@
         void
         u3m_wall(u3_noun wol);
 
-      /* u3m_reclaim: clear persistent caches to reclaim memory
+      /* u3m_reclaim: clear persistent caches to reclaim memory.
       */
         void
         u3m_reclaim(void);
@@ -195,10 +198,4 @@
         c3_w
         u3m_pack(void);
 
-      /* u3m_migrate: perform loom migration if necessary.
-         ver_w - target version
-      */
-        void
-        u3m_migrate(u3v_version ver_w);
-
 #endif /* ifndef U3_MANAGE_H */
diff --git a/pkg/noun/nock.c b/pkg/noun/nock.c
index 6ac08779ef..452b04c309 100644
--- a/pkg/noun/nock.c
+++ b/pkg/noun/nock.c
@@ -619,7 +619,7 @@ _n_melt(u3_noun ops, c3_w* byc_w, c3_w* cal_w,
 
         case SKIB: case SLIB: {
           c3_l tot_l = 0,
-               sip_l = u3h(u3t(op));
+               sip_l = u3h(u3t(u3t(op)));
           c3_w j_w, k_w = i_w;
           for ( j_w = 0; j_w < sip_l; ++j_w ) {
             tot_l += siz_y[++k_w];
@@ -830,7 +830,9 @@ _n_prog_asm(u3_noun ops, u3n_prog* pog_u, u3_noun sip)
           _n_prog_asm_inx(buf_y, &i_w, mem_s, cod);
           mem_u        = &(pog_u->mem_u.sot_u[mem_s++]);
           mem_u->sip_l = sip_l;
-          mem_u->key   = u3k(u3t(u3t(op)));
+          // [op_y, cid, mem_w, nef]
+          mem_u->key   = u3k(u3t(u3t(u3t(op))));
+          mem_u->cid   = u3h(u3t(op));
           break;
         }
 
@@ -1117,16 +1119,21 @@ _n_bint(u3_noun* ops, u3_noun hif, u3_noun nef, c3_o los_o, c3_o tel_o)
         c3_w mem_w = 0;
         c3_y op_y;
 
-        // we just throw away the hint (why is this not a static hint?)
         tot_w += _n_comp(ops, hod, c3n, c3n);
         ++tot_w; _n_emit(ops, TOSS);
 
-        // memoizing code always loses TOS because SAVE needs [pro key]
         mem_w += _n_comp(&mem, nef, c3y, c3n);
         ++mem_w; _n_emit(&mem, SAVE);
 
         op_y   = (c3y == los_o) ? SLIB : SKIB; // overflows to SLIS / SKIS
-        ++tot_w; _n_emit(ops, u3nt(op_y, mem_w, u3k(nef)));
+        u3z_cid cid = u3z_memo_toss;
+        {
+          u3_weak con = u3r_skip(hod);
+          if ( (u3_none != con) && (c3y == u3du(con)) ) {
+            cid = u3z_memo_keep;
+          }
+        }
+        ++tot_w; _n_emit(ops, u3nq(op_y, cid, mem_w, u3k(nef)));
         tot_w += mem_w; _n_apen(ops, mem);
         break;
       }
@@ -2610,9 +2617,9 @@ _n_burn(u3n_prog* pog_u, u3_noun bus, c3_ys mov, c3_ys off)
     skim_out:
       o     = u3k(mem_u->key);
       x     = u3nc(x, o);
-      o     = u3z_find_m(144 + c3__nock, x);
+      o     = u3z_find_m(mem_u->cid, 144 + c3__nock, x);
       if ( u3_none == o ) {
-        _n_push(mov, off, x);
+        _n_push(mov, off, u3nc(mem_u->cid, x));
         _n_push(mov, off, u3k(u3h(x)));
       }
       else {
@@ -2623,11 +2630,16 @@ _n_burn(u3n_prog* pog_u, u3_noun bus, c3_ys mov, c3_ys off)
       BURN();
 
     do_save:
-      x   = _n_pep(mov, off);
+      x   = _n_pep(mov, off);  // product
       top = _n_peek(off);
       o   = *top;
-      if ( &(u3H->rod_u) != u3R ) {
-        u3z_save_m(144 + c3__nock, o, x);
+      if ( ( u3z_memo_toss == u3h(o) )
+         ? ( &(u3H->rod_u) != u3R )
+         : ( 0 == u3R->ski.gul ) ) {  //  prevents userspace from persistence
+        u3z_save_m(u3h(o), 144 + c3__nock, u3t(o), x);
+      }
+      else if ( u3z_memo_keep == u3h(o) ) {
+        fprintf(stderr, "\r\nnock: userspace can't save to persistent cache\r\n");
       }
       *top = x;
       u3z(o);
@@ -2853,6 +2865,7 @@ _cn_take_prog_dat(u3n_prog* dst_u, u3n_prog* src_u)
     u3n_memo* ome_u = &(dst_u->mem_u.sot_u[i_w]);
     ome_u->sip_l    = emo_u->sip_l;
     ome_u->key      = u3a_take(emo_u->key);
+    ome_u->cid      = emo_u->cid;
   }
 
   for ( i_w = 0; i_w < src_u->cal_u.len_w; ++i_w ) {
@@ -2918,6 +2931,7 @@ _cn_merge_prog_dat(u3n_prog* dst_u, u3n_prog* src_u)
     u3z(emo_u->key);
     emo_u->sip_l    = ome_u->sip_l;
     emo_u->key      = ome_u->key;
+    emo_u->cid      = ome_u->cid;
   }
 
   for ( i_w = 0; i_w < src_u->cal_u.len_w; ++i_w ) {
diff --git a/pkg/noun/nock.h b/pkg/noun/nock.h
index 7dded22058..7baf7351d8 100644
--- a/pkg/noun/nock.h
+++ b/pkg/noun/nock.h
@@ -8,6 +8,7 @@
 #include "c3.h"
 #include "jets.h"
 #include "types.h"
+#include "zave.h"
 
   /** Data structures.
   ***
@@ -18,6 +19,7 @@
   typedef struct {
     c3_l    sip_l;
     u3_noun key;
+    u3z_cid cid;
   } u3n_memo;
 
   /* u3n_prog: program compiled from nock
diff --git a/pkg/noun/options.h b/pkg/noun/options.h
index 1bd65320fc..29ca6ce9d9 100644
--- a/pkg/noun/options.h
+++ b/pkg/noun/options.h
@@ -15,16 +15,10 @@
         c3_c*   dir_c;                        //  execution directory (pier)
         c3_c*   eph_c;                        //  ephemeral file
         c3_w    wag_w;                        //  flags (both ways)
-        c3_w    vits_w;                       //  number of virtual bits in reference
-        c3_w    walign_w;                     //  word alignment
-        c3_d    balign_d;                     //  byte alignment
-        enum {
-          MIG_NONE,
-          MIG_REWRITE_COMPRESSED,
-        } migration_state;
-
         size_t  wor_i;                        //  loom word-length (<= u3a_words)
         c3_w    tos_w;                        //  loom toss skip-length
+        c3_w    hap_w;                        //  transient memoization cache size
+        c3_w    per_w;                        //  persistent memoization cache size
         void (*stderr_log_f)(c3_c*);          //  errors from c code
         void (*slog_f)(u3_noun);              //  function pointer for slog
         void (*sign_hold_f)(void);            //  suspend system signal regime
diff --git a/pkg/noun/retrieve.c b/pkg/noun/retrieve.c
index c5f20d0c27..8f9847ff92 100644
--- a/pkg/noun/retrieve.c
+++ b/pkg/noun/retrieve.c
@@ -1827,3 +1827,29 @@ u3r_mug(u3_noun veb)
 
   return mug_l;
 }
+
+/* u3r_skip():
+**
+**  Extract a constant from a formula, ignoring
+**  safe/static hints, doing no computation.
+*/
+u3_weak
+u3r_skip(u3_noun fol)
+{
+  while ( c3y == u3du(fol) ) {
+    switch ( u3h(fol) ) {
+      default: return u3_none;
+      case 1:  return u3t(fol);
+      case 11: {
+        u3_noun arg = u3t(fol),
+                hod = u3h(arg);
+
+        if ( (c3y == u3du(hod)) && (u3_none == u3r_skip(u3t(hod))) ) {
+          return u3_none;
+        }
+        fol = u3t(arg);
+      }
+    }
+  }
+  return u3_none;
+}
diff --git a/pkg/noun/retrieve.h b/pkg/noun/retrieve.h
index 0b77708b47..7423ad9f49 100644
--- a/pkg/noun/retrieve.h
+++ b/pkg/noun/retrieve.h
@@ -527,4 +527,12 @@
         c3_y*
         u3r_tape(u3_noun a);
 
+      /* u3r_skip():
+      **
+      **  Extract a constant from a formula, ignoring
+      **  safe/static hints, doing no computation.
+      */
+        u3_weak
+        u3r_skip(u3_noun fol);
+
 #endif /* ifndef U3_RETRIEVE_H */
diff --git a/pkg/noun/v1/allocate.c b/pkg/noun/v1/allocate.c
new file mode 100644
index 0000000000..7ce4521ecc
--- /dev/null
+++ b/pkg/noun/v1/allocate.c
@@ -0,0 +1,238 @@
+/// @file
+
+#include "pkg/noun/allocate.h"
+#include "pkg/noun/v1/allocate.h"
+
+#include "pkg/noun/v1/hashtable.h"
+
+/* _box_v1_slot(): select the right free list to search for a block.
+*/
+static c3_w
+_box_v1_slot(c3_w siz_w)
+{
+  if ( siz_w < u3a_v1_minimum ) {
+    return 0;
+  }
+  else {
+    c3_w i_w = 1;
+
+    while ( 1 ) {
+      if ( i_w == u3a_v1_fbox_no ) {
+        return (i_w - 1);
+      }
+      if ( siz_w < 16 ) {
+        return i_w;
+      }
+      siz_w = (siz_w + 1) >> 1;
+      i_w += 1;
+    }
+  }
+}
+
+/* _box_v1_make(): construct a box.
+*/
+static u3a_v1_box*
+_box_v1_make(void* box_v, c3_w siz_w, c3_w use_w)
+{
+  u3a_v1_box* box_u = box_v;
+  c3_w*    box_w = box_v;
+
+  u3_assert(siz_w >= u3a_v1_minimum);
+
+  box_w[0] = siz_w;
+  box_w[siz_w - 1] = siz_w;
+  box_u->use_w = use_w;
+
+# ifdef  U3_MEMORY_DEBUG
+    box_u->cod_w = u3_Code;
+    box_u->eus_w = 0;
+# endif
+
+  return box_u;
+}
+
+/* _box_v1_attach(): attach a box to the free list.
+*/
+static void
+_box_v1_attach(u3a_v1_box* box_u)
+{
+  u3_assert(box_u->siz_w >= (1 + c3_wiseof(u3a_v1_fbox)));
+  u3_assert(0 != u3of(u3a_v1_fbox, box_u));
+
+  {
+    c3_w           sel_w = _box_v1_slot(box_u->siz_w);
+    u3p(u3a_v1_fbox)  fre_p = u3of(u3a_v1_fbox, box_u);
+    u3p(u3a_v1_fbox)* pfr_p = &u3R_v1->all.fre_p[sel_w];
+    u3p(u3a_v1_fbox)  nex_p = *pfr_p;
+
+    u3to(u3a_v1_fbox, fre_p)->pre_p = 0;
+    u3to(u3a_v1_fbox, fre_p)->nex_p = nex_p;
+    if ( u3to(u3a_v1_fbox, fre_p)->nex_p ) {
+      u3to(u3a_v1_fbox, u3to(u3a_v1_fbox, fre_p)->nex_p)->pre_p = fre_p;
+    }
+    (*pfr_p) = fre_p;
+  }
+}
+
+/* _box_v1_detach(): detach a box from the free list.
+*/
+static void
+_box_v1_detach(u3a_v1_box* box_u)
+{
+  u3p(u3a_v1_fbox) fre_p = u3of(u3a_v1_fbox, box_u);
+  u3p(u3a_v1_fbox) pre_p = u3to(u3a_v1_fbox, fre_p)->pre_p;
+  u3p(u3a_v1_fbox) nex_p = u3to(u3a_v1_fbox, fre_p)->nex_p;
+
+
+  if ( nex_p ) {
+    if ( u3to(u3a_v1_fbox, nex_p)->pre_p != fre_p ) {
+      u3_assert(!"loom: corrupt");
+    }
+    u3to(u3a_v1_fbox, nex_p)->pre_p = pre_p;
+  }
+  if ( pre_p ) {
+    if( u3to(u3a_v1_fbox, pre_p)->nex_p != fre_p ) {
+      u3_assert(!"loom: corrupt");
+    }
+    u3to(u3a_v1_fbox, pre_p)->nex_p = nex_p;
+  }
+  else {
+    c3_w sel_w = _box_v1_slot(box_u->siz_w);
+
+    if ( fre_p != u3R_v1->all.fre_p[sel_w] ) {
+      u3_assert(!"loom: corrupt");
+    }
+    u3R_v1->all.fre_p[sel_w] = nex_p;
+  }
+}
+
+/* _box_v1_free(): free and coalesce.
+*/
+static void
+_box_v1_free(u3a_v1_box* box_u)
+{
+  c3_w* box_w = (c3_w *)(void *)box_u;
+
+  u3_assert(box_u->use_w != 0);
+  box_u->use_w -= 1;
+  if ( 0 != box_u->use_w ) {
+    return;
+  }
+
+  //  we're always migrating a north road, so no need to check for it
+  {
+    /* Try to coalesce with the block below.
+    */
+    if ( box_w != u3a_v1_into(u3R_v1->rut_p) ) {
+      c3_w       laz_w = *(box_w - 1);
+      u3a_v1_box* pox_u = (u3a_v1_box*)(void *)(box_w - laz_w);
+
+      if ( 0 == pox_u->use_w ) {
+        _box_v1_detach(pox_u);
+        _box_v1_make(pox_u, (laz_w + box_u->siz_w), 0);
+
+        box_u = pox_u;
+        box_w = (c3_w*)(void *)pox_u;
+      }
+    }
+
+    /* Try to coalesce with the block above, or the wilderness.
+    */
+    if ( (box_w + box_u->siz_w) == u3a_v1_into(u3R_v1->hat_p) ) {
+      u3R_v1->hat_p = u3a_v1_outa(box_w);
+    }
+    else {
+      u3a_v1_box* nox_u = (u3a_v1_box*)(void *)(box_w + box_u->siz_w);
+
+      if ( 0 == nox_u->use_w ) {
+        _box_v1_detach(nox_u);
+        _box_v1_make(box_u, (box_u->siz_w + nox_u->siz_w), 0);
+      }
+      _box_v1_attach(box_u);
+    }
+  }
+}
+
+/* u3a_v1_wfree(): free storage.
+*/
+void
+u3a_v1_wfree(void* tox_v)
+{
+  _box_v1_free(u3a_v1_botox(tox_v));
+}
+
+/* u3a_v1_free(): free for aligned malloc.
+*/
+void
+u3a_v1_free(void* tox_v)
+{
+  if (NULL == tox_v)
+    return;
+
+  c3_w* tox_w = tox_v;
+  c3_w  pad_w = tox_w[-1];
+  c3_w* org_w = tox_w - (pad_w + 1);
+
+  // u3l_log("free %p %p", org_w, tox_w);
+  u3a_v1_wfree(org_w);
+}
+
+/* u3a_v1_reclaim(): clear ad-hoc persistent caches to reclaim memory.
+*/
+void
+u3a_v1_reclaim(void)
+{
+  //  clear the memoization cache
+  //
+  u3h_v1_free_nodes(u3R_v1->cax.har_p);
+}
+
+/* _me_v1_lose_north(): lose on a north road.
+*/
+static void
+_me_v1_lose_north(u3_noun dog)
+{
+top:
+  {
+    c3_w* dog_w      = u3a_v1_to_ptr(dog);
+    u3a_v1_box* box_u = u3a_v1_botox(dog_w);
+
+    if ( box_u->use_w > 1 ) {
+      box_u->use_w -= 1;
+    }
+    else {
+      if ( 0 == box_u->use_w ) {
+        u3m_v1_bail(c3__foul);
+      }
+      else {
+        if ( _(u3a_v1_is_pom(dog)) ) {
+          u3a_v1_cell* dog_u = (void *)dog_w;
+          u3_noun     h_dog = dog_u->hed;
+          u3_noun     t_dog = dog_u->tel;
+
+          if ( !_(u3a_v1_is_cat(h_dog)) ) {
+            _me_v1_lose_north(h_dog);
+          }
+          u3a_v1_wfree(dog_w);
+          if ( !_(u3a_v1_is_cat(t_dog)) ) {
+            dog = t_dog;
+            goto top;
+          }
+        }
+        else {
+          u3a_v1_wfree(dog_w);
+        }
+      }
+    }
+  }
+}
+
+/* u3a_v1_lose(): lose a reference count.
+*/
+void
+u3a_v1_lose(u3_noun som)
+{
+  if ( !_(u3a_v1_is_cat(som)) ) {
+    _me_v1_lose_north(som);
+  }
+}
diff --git a/pkg/noun/v1/allocate.h b/pkg/noun/v1/allocate.h
new file mode 100644
index 0000000000..4544417b78
--- /dev/null
+++ b/pkg/noun/v1/allocate.h
@@ -0,0 +1,78 @@
+#ifndef U3_ALLOCATE_V1_H
+#define U3_ALLOCATE_V1_H
+
+#include "pkg/noun/allocate.h"
+#include "pkg/noun/v2/allocate.h"
+
+  /**  Aliases.
+  **/
+#     define u3R_v1           u3R_v2
+#     define u3a_v1_botox     u3a_v2_botox
+#     define u3a_v1_box       u3a_v2_box
+#     define u3a_v1_cell      u3a_v2_cell
+#     define u3a_v1_fbox      u3a_v2_fbox
+#     define u3a_v1_fbox_no   u3a_v2_fbox_no
+#     define u3a_v1_into      u3a_v2_into
+#     define u3a_v1_is_cat    u3a_v2_is_cat
+#     define u3a_v1_is_north  u3a_v2_is_north
+#     define u3a_v1_is_pom    u3a_v2_is_pom
+#     define u3a_v1_minimum   u3a_v2_minimum
+#     define u3a_v1_outa      u3a_v2_outa
+
+  /**  Structures.
+  **/
+  /**  Macros.  Should be better commented.
+  **/
+    /* Inside a noun.
+    */
+    /* u3a_v1_to_off(): mask off bits 30 and 31 from noun [som].
+    */
+#     define u3a_v1_to_off(som)    ((som) & 0x3fffffff)
+
+    /* u3a_v1_to_ptr(): convert noun [som] into generic pointer into loom.
+    */
+#     define u3a_v1_to_ptr(som)    (u3a_v1_into(u3a_v1_to_off(som)))
+
+    /* u3a_v1_to_wtr(): convert noun [som] into word pointer into loom.
+    */
+#     define u3a_v1_to_wtr(som)    ((c3_w *)u3a_v1_to_ptr(som))
+
+    /* u3a_v1_to_pug(): set bit 31 of [off].
+    */
+#     define u3a_v1_to_pug(off)    (off | 0x80000000)
+
+    /* u3a_v1_to_pom(): set bits 30 and 31 of [off].
+    */
+#     define u3a_v1_to_pom(off)    (off | 0xc0000000)
+
+  /**  Functions.
+  **/
+    /**  Allocation.
+    **/
+      /* Word-aligned allocation.
+      */
+        /* u3a_v1_wfree(): free storage.
+        */
+          void
+          u3a_v1_wfree(void* lag_v);
+
+      /* C-style aligned allocation - *not* compatible with above.
+      */
+        /* u3a_v1_free(): free for aligned malloc.
+        */
+          void
+          u3a_v1_free(void* tox_v);
+
+      /* Reference and arena control.
+      */
+        /* u3a_v1_reclaim(): clear ad-hoc persistent caches to reclaim memory.
+        */
+          void
+          u3a_v1_reclaim(void);
+
+        /* u3a_v1_lose(): lose a reference count.
+        */
+          void
+          u3a_v1_lose(u3_noun som);
+
+#endif /* ifndef U3_ALLOCATE_H */
diff --git a/pkg/noun/v1/hashtable.c b/pkg/noun/v1/hashtable.c
new file mode 100644
index 0000000000..aa3a9b7aef
--- /dev/null
+++ b/pkg/noun/v1/hashtable.c
@@ -0,0 +1,173 @@
+/// @file
+
+#include "pkg/noun/hashtable.h"
+#include "pkg/noun/v1/hashtable.h"
+
+#include "pkg/noun/allocate.h"
+#include "pkg/noun/v1/allocate.h"
+
+
+/* _ch_v1_popcount(): number of bits set in word.  A standard intrinsic.
+**             NB: copy of _ch_v1_popcount in pkg/noun/hashtable.c
+*/
+static c3_w
+_ch_v1_popcount(c3_w num_w)
+{
+  return __builtin_popcount(num_w);
+}
+
+/* _ch_v1_free_buck(): free bucket
+**              NB: copy of _ch_v1_free_buck in pkg/noun/hashtable.c
+*/
+static void
+_ch_v1_free_buck(u3h_v1_buck* hab_u)
+{
+  c3_w i_w;
+
+  for ( i_w = 0; i_w < hab_u->len_w; i_w++ ) {
+    u3a_v1_lose(u3h_v1_slot_to_noun(hab_u->sot_w[i_w]));
+  }
+  u3a_v1_wfree(hab_u);
+}
+
+/* _ch_v1_free_node(): free node.
+*/
+static void
+_ch_v1_free_node(u3h_v1_node* han_u, c3_w lef_w)
+{
+  c3_w len_w = _ch_v1_popcount(han_u->map_w);
+  c3_w i_w;
+
+  lef_w -= 5;
+
+  for ( i_w = 0; i_w < len_w; i_w++ ) {
+    c3_w sot_w = han_u->sot_w[i_w];
+
+    if ( _(u3h_v1_slot_is_noun(sot_w)) ) {
+      u3a_v1_lose(u3h_v1_slot_to_noun(sot_w));
+    }
+    else {
+      void* hav_v = u3h_v1_slot_to_node(sot_w);
+
+      if ( 0 == lef_w ) {
+        _ch_v1_free_buck(hav_v);
+      } else {
+        _ch_v1_free_node(hav_v, lef_w);
+      }
+    }
+  }
+  u3a_v1_wfree(han_u);
+}
+
+/* u3h_v1_free_nodes(): free hashtable nodes.
+*/
+void
+u3h_v1_free_nodes(u3p(u3h_v1_root) har_p)
+{
+  u3h_v1_root* har_u = u3to(u3h_v1_root, har_p);
+  c3_w        i_w;
+
+  for ( i_w = 0; i_w < 64; i_w++ ) {
+    c3_w sot_w = har_u->sot_w[i_w];
+
+    if ( _(u3h_v1_slot_is_noun(sot_w)) ) {
+      u3a_v1_lose(u3h_v1_slot_to_noun(sot_w));
+    }
+    else if ( _(u3h_v1_slot_is_node(sot_w)) ) {
+      u3h_v1_node* han_u = (u3h_v1_node*) u3h_v1_slot_to_node(sot_w);
+
+      _ch_v1_free_node(han_u, 25);
+    }
+    har_u->sot_w[i_w] = 0;
+  }
+  har_u->use_w       = 0;
+  har_u->arm_u.mug_w = 0;
+  har_u->arm_u.inx_w = 0;
+}
+
+/* _ch_v1_walk_buck(): walk bucket for gc.
+**              NB: copy of _ch_v1_walk_buck in pkg/noun/hashtable.c
+*/
+static void
+_ch_v1_walk_buck(u3h_v1_buck* hab_u, void (*fun_f)(u3_noun, void*), void* wit)
+{
+  c3_w i_w;
+
+  for ( i_w = 0; i_w < hab_u->len_w; i_w++ ) {
+    fun_f(u3h_v1_slot_to_noun(hab_u->sot_w[i_w]), wit);
+  }
+}
+
+/* _ch_v1_walk_node(): walk node for gc.
+*/
+static void
+_ch_v1_walk_node(u3h_v1_node* han_u, c3_w lef_w, void (*fun_f)(u3_noun, void*), void* wit)
+{
+  c3_w len_w = _ch_v1_popcount(han_u->map_w);
+  c3_w i_w;
+
+  lef_w -= 5;
+
+  for ( i_w = 0; i_w < len_w; i_w++ ) {
+    c3_w sot_w = han_u->sot_w[i_w];
+
+    if ( _(u3h_v1_slot_is_noun(sot_w)) ) {
+      u3_noun kev = u3h_v1_slot_to_noun(sot_w);
+
+      fun_f(kev, wit);
+    }
+    else {
+      void* hav_v = u3h_v1_slot_to_node(sot_w);
+
+      if ( 0 == lef_w ) {
+        _ch_v1_walk_buck(hav_v, fun_f, wit);
+      } else {
+        _ch_v1_walk_node(hav_v, lef_w, fun_f, wit);
+      }
+    }
+  }
+}
+
+/* u3h_v1_walk_with(): traverse hashtable with key, value fn and data
+ *                  argument; RETAINS.
+*/
+void
+u3h_v1_walk_with(u3p(u3h_v1_root) har_p,
+              void (*fun_f)(u3_noun, void*),
+              void* wit)
+{
+  u3h_v1_root* har_u = u3to(u3h_v1_root, har_p);
+  c3_w        i_w;
+
+  for ( i_w = 0; i_w < 64; i_w++ ) {
+    c3_w sot_w = har_u->sot_w[i_w];
+
+    if ( _(u3h_v1_slot_is_noun(sot_w)) ) {
+      u3_noun kev = u3h_v1_slot_to_noun(sot_w);
+
+      fun_f(kev, wit);
+    }
+    else if ( _(u3h_v1_slot_is_node(sot_w)) ) {
+      u3h_v1_node* han_u = (u3h_v1_node*) u3h_v1_slot_to_node(sot_w);
+
+      _ch_v1_walk_node(han_u, 25, fun_f, wit);
+    }
+  }
+}
+
+/* _ch_v1_walk_plain(): use plain u3_noun fun_f for each node
+ */
+static void
+_ch_v1_walk_plain(u3_noun kev, void* wit)
+{
+  void (*fun_f)(u3_noun) = wit;
+  fun_f(kev);
+}
+
+/* u3h_v1_walk(): u3h_v1_walk_with, but with no data argument
+*/
+void
+u3h_v1_walk(u3p(u3h_v1_root) har_p, void (*fun_f)(u3_noun))
+{
+  u3h_v1_walk_with(har_p, _ch_v1_walk_plain, fun_f);
+}
diff --git a/pkg/noun/v1/hashtable.h b/pkg/noun/v1/hashtable.h
new file mode 100644
index 0000000000..2d5fdea6f3
--- /dev/null
+++ b/pkg/noun/v1/hashtable.h
@@ -0,0 +1,51 @@
+#ifndef U3_HASHTABLE_V1_H
+#define U3_HASHTABLE_V1_H
+
+#include "pkg/noun/hashtable.h"
+#include "pkg/noun/v2/hashtable.h"
+
+  /**  Aliases.
+  **/
+#     define  u3h_v1_buck          u3h_v2_buck
+#     define  u3h_v1_node          u3h_v2_node
+#     define  u3h_v1_root          u3h_v2_root
+#     define  u3h_v1_slot_is_node  u3h_v2_slot_is_node
+#     define  u3h_v1_slot_is_noun  u3h_v2_slot_is_noun
+#     define  u3h_v1_slot_to_noun  u3h_v2_slot_to_noun
+
+  /**  Data structures.
+  **/
+
+    /**  HAMT macros.
+    ***
+    ***  Coordinate with u3_noun definition!
+    **/
+      /* u3h_v1_slot_to_node(): slot to node pointer
+      ** u3h_v1_node_to_slot(): node pointer to slot
+      */
+#     define  u3h_v1_slot_to_node(sot)  (u3a_v1_into((sot) & 0x3fffffff))
+#     define  u3h_v1_node_to_slot(ptr)  (u3a_v1_outa(ptr) | 0x40000000)
+
+    /**  Functions.
+    ***
+    ***  Needs: delete and merge functions; clock reclamation function.
+    **/
+      /* u3h_v1_free(): free hashtable.
+      */
+        void
+        u3h_v1_free_nodes(u3p(u3h_root) har_p);
+
+      /* u3h_v1_walk_with(): traverse hashtable with key, value fn and data
+       *                  argument; RETAINS.
+      */
+        void
+        u3h_v1_walk_with(u3p(u3h_root) har_p,
+                      void (*fun_f)(u3_noun, void*),
+                      void* wit);
+
+      /* u3h_v1_walk(): u3h_v1_walk_with, but with no data argument
+      */
+        void
+        u3h_v1_walk(u3p(u3h_root) har_p, void (*fun_f)(u3_noun));
+
+#endif /* ifndef U3_HASHTABLE_H */
diff --git a/pkg/noun/v1/jets.c b/pkg/noun/v1/jets.c
new file mode 100644
index 0000000000..272930e11d
--- /dev/null
+++ b/pkg/noun/v1/jets.c
@@ -0,0 +1,87 @@
+/// @file
+
+#include "pkg/noun/vortex.h"
+
+#include "pkg/noun/jets.h"
+#include "pkg/noun/v1/jets.h"
+#include "pkg/noun/v2/jets.h"
+
+#include "pkg/noun/v1/allocate.h"
+#include "pkg/noun/v1/hashtable.h"
+
+
+/* _cj_fink_free(): lose and free everything in a u3j_v1_fink.
+*/
+static void
+_cj_v1_fink_free(u3p(u3j_v1_fink) fin_p)
+{
+  c3_w i_w;
+  u3j_v1_fink* fin_u = u3to(u3j_v1_fink, fin_p);
+  u3a_v1_lose(fin_u->sat);
+  for ( i_w = 0; i_w < fin_u->len_w; ++i_w ) {
+    u3j_v1_fist* fis_u = &(fin_u->fis_u[i_w]);
+    u3a_v1_lose(fis_u->bat);
+    u3a_v1_lose(fis_u->pax);
+  }
+  u3a_v1_wfree(fin_u);
+}
+
+/* u3j_v1_rite_lose(): lose references of u3j_v1_rite (but do not free).
+ */
+void
+u3j_v1_rite_lose(u3j_v1_rite* rit_u)
+{
+  if ( (c3y == rit_u->own_o) && u3_none != rit_u->clu ) {
+    u3a_v1_lose(rit_u->clu);
+    _cj_v1_fink_free(rit_u->fin_p);
+  }
+}
+
+
+/* u3j_v1_site_lose(): lose references of u3j_v1_site (but do not free).
+ */
+void
+u3j_v1_site_lose(u3j_v1_site* sit_u)
+{
+  u3a_v1_lose(sit_u->axe);
+  if ( u3_none != sit_u->bat ) {
+    u3a_v1_lose(sit_u->bat);
+  }
+  if ( u3_none != sit_u->bas ) {
+    u3a_v1_lose(sit_u->bas);
+  }
+  if ( u3_none != sit_u->loc ) {
+    u3a_v1_lose(sit_u->loc);
+    u3a_v1_lose(sit_u->lab);
+    if ( c3y == sit_u->fon_o ) {
+      if ( sit_u->fin_p ) {
+      _cj_v1_fink_free(sit_u->fin_p);
+      }
+    }
+  }
+}
+
+/* _cj_v1_free_hank(): free an entry from the hank cache.
+*/
+static void
+_cj_v1_free_hank(u3_noun kev)
+{
+  u3a_v1_cell* cel_u = (u3a_v1_cell*) u3a_v1_to_ptr(kev);
+  u3j_v1_hank* han_u = u3to(u3j_v1_hank, cel_u->tel);
+  if ( u3_none != han_u->hax ) {
+    u3a_v1_lose(han_u->hax);
+    u3j_v1_site_lose(&(han_u->sit_u));
+  }
+  u3a_v1_wfree(han_u);
+}
+
+/* u3j_v1_reclaim(): clear ad-hoc persistent caches to reclaim memory.
+*/
+void
+u3j_v1_reclaim(void)
+{
+  //  clear the jet hank cache
+  //
+  u3h_v1_walk(u3R_v1->jed.han_p, _cj_v1_free_hank);
+  u3h_v1_free_nodes(u3R_v1->jed.han_p);
+}
diff --git a/pkg/noun/v1/jets.h b/pkg/noun/v1/jets.h
new file mode 100644
index 0000000000..bf3dfe6afe
--- /dev/null
+++ b/pkg/noun/v1/jets.h
@@ -0,0 +1,34 @@
+/// @file
+
+#ifndef U3_JETS_V1_H
+#define U3_JETS_V1_H
+
+#include "pkg/noun/jets.h"
+#include "pkg/noun/v2/jets.h"
+
+  /**  Aliases.
+  **/
+#     define u3j_v1_fink       u3j_v2_fink
+#     define u3j_v1_fist       u3j_v2_fist
+#     define u3j_v1_hank       u3j_v2_hank
+#     define u3j_v1_rite       u3j_v2_rite
+#     define u3j_v1_site       u3j_v2_site
+
+  /**  Functions.
+  **/
+    /* u3j_v1_reclaim(): clear ad-hoc persistent caches to reclaim memory.
+    */
+      void
+      u3j_v1_reclaim(void);
+
+    /* u3j_v1_rite_lose(): lose references of u3j_rite (but do not free).
+    */
+      void
+      u3j_v1_rite_lose(u3j_v1_rite* rit_u);
+
+    /* u3j_v1_site_lose(): lose references of u3j_site (but do not free).
+    */
+      void
+      u3j_v1_site_lose(u3j_v1_site* sit_u);
+
+#endif /* ifndef U3_JETS_V1_H */
diff --git a/pkg/noun/v1/manage.c b/pkg/noun/v1/manage.c
new file mode 100644
index 0000000000..0eac6a8d7b
--- /dev/null
+++ b/pkg/noun/v1/manage.c
@@ -0,0 +1,20 @@
+/// @file
+
+#include "pkg/noun/v1/manage.h"
+
+#include "pkg/noun/v1/allocate.h"
+#include "pkg/noun/v1/hashtable.h"
+#include "pkg/noun/v1/jets.h"
+#include "pkg/noun/v1/nock.h"
+#include "pkg/noun/v1/vortex.h"
+
+/* u3m_v1_reclaim: clear persistent caches to reclaim memory
+*/
+void
+u3m_v1_reclaim(void)
+{
+  u3v_v1_reclaim();
+  u3j_v1_reclaim();
+  u3n_v1_reclaim();
+  u3a_v1_reclaim();
+}
diff --git a/pkg/noun/v1/manage.h b/pkg/noun/v1/manage.h
new file mode 100644
index 0000000000..669d69ea36
--- /dev/null
+++ b/pkg/noun/v1/manage.h
@@ -0,0 +1,17 @@
+/// @file
+
+#ifndef U3_MANAGE_V1_H
+#define U3_MANAGE_V1_H
+
+    /** Aliases.
+    **/
+#     define  u3m_v1_bail  u3m_bail
+
+    /** System management.
+    **/
+      /* u3m_v1_reclaim: clear persistent caches to reclaim memory
+      */
+        void
+        u3m_v1_reclaim(void);
+
+#endif /* ifndef U3_MANAGE_V1_H */
diff --git a/pkg/noun/v1/nock.c b/pkg/noun/v1/nock.c
new file mode 100644
index 0000000000..1ac2931a97
--- /dev/null
+++ b/pkg/noun/v1/nock.c
@@ -0,0 +1,69 @@
+/// @file
+
+#include "pkg/noun/nock.h"
+#include "pkg/noun/v1/nock.h"
+
+#include "pkg/noun/v1/allocate.h"
+#include "pkg/noun/v1/hashtable.h"
+#include "pkg/noun/jets.h"
+#include "pkg/noun/v1/jets.h"
+
+/* u3n_v1_reclaim(): clear ad-hoc persistent caches to reclaim memory.
+*/
+void
+u3n_v1_reclaim(void)
+{
+  //  clear the bytecode cache
+  //
+  //    We can't just u3h_v1_free() -- the value is a post to a u3n_v1_prog.
+  //    Note that the hank cache *must* also be freed (in u3j_v1_reclaim())
+  //
+  u3n_v1_free();
+}
+
+/* _cn_v1_prog_free(): free memory retained by program pog_u
+*/
+static void
+_cn_v1_prog_free(u3n_v1_prog* pog_u)
+{
+  // fix up pointers for loom portability
+  pog_u->byc_u.ops_y = (c3_y*) ((void*) pog_u) + sizeof(u3n_v1_prog);
+  pog_u->lit_u.non   = (u3_noun*) (pog_u->byc_u.ops_y + pog_u->byc_u.len_w);
+  pog_u->mem_u.sot_u = (u3n_v1_memo*) (pog_u->lit_u.non + pog_u->lit_u.len_w);
+  pog_u->cal_u.sit_u = (u3j_v1_site*) (pog_u->mem_u.sot_u + pog_u->mem_u.len_w);
+  pog_u->reg_u.rit_u = (u3j_v1_rite*) (pog_u->cal_u.sit_u + pog_u->cal_u.len_w);
+
+  c3_w dex_w;
+  for (dex_w = 0; dex_w < pog_u->lit_u.len_w; ++dex_w) {
+    u3a_v1_lose(pog_u->lit_u.non[dex_w]);
+  }
+  for (dex_w = 0; dex_w < pog_u->mem_u.len_w; ++dex_w) {
+    u3a_v1_lose(pog_u->mem_u.sot_u[dex_w].key);
+  }
+  for (dex_w = 0; dex_w < pog_u->cal_u.len_w; ++dex_w) {
+    u3j_v1_site_lose(&(pog_u->cal_u.sit_u[dex_w]));
+  }
+  for (dex_w = 0; dex_w < pog_u->reg_u.len_w; ++dex_w) {
+    u3j_v1_rite_lose(&(pog_u->reg_u.rit_u[dex_w]));
+  }
+  u3a_v1_free(pog_u);
+}
+
+/* _n_v1_feb(): u3h_v1_walk helper for u3n_v1_free
+ */
+static void
+_n_v1_feb(u3_noun kev)
+{
+  u3a_v1_cell *cel_u = (u3a_v1_cell*) u3a_v1_to_ptr(kev);
+  _cn_v1_prog_free(u3to(u3n_v1_prog, cel_u->tel));
+}
+
+/* u3n_v1_free(): free bytecode cache
+ */
+void
+u3n_v1_free()
+{
+  u3p(u3h_v1_root) har_p = u3R_v1->byc.har_p;
+  u3h_v1_walk(har_p, _n_v1_feb);
+  u3h_v1_free_nodes(har_p);
+}
diff --git a/pkg/noun/v1/nock.h b/pkg/noun/v1/nock.h
new file mode 100644
index 0000000000..5320307b6b
--- /dev/null
+++ b/pkg/noun/v1/nock.h
@@ -0,0 +1,25 @@
+/// @file
+
+#ifndef U3_NOCK_V1_H
+#define U3_NOCK_V1_H
+
+#include "pkg/noun/v2/nock.h"
+
+  /**  Aliases.
+  **/
+#     define  u3n_v1_memo  u3n_v2_memo
+#     define  u3n_v1_prog  u3n_v2_prog
+
+  /**  Functions.
+  **/
+    /* u3n_v1_reclaim(): clear ad-hoc persistent caches to reclaim memory.
+    */
+      void
+      u3n_v1_reclaim(void);
+
+    /* u3n_v1_free(): free bytecode cache.
+     */
+      void
+      u3n_v1_free(void);
+
+#endif /* ifndef U3_NOCK_V1_H */
diff --git a/pkg/noun/v1/vortex.c b/pkg/noun/v1/vortex.c
new file mode 100644
index 0000000000..e1ec21b22d
--- /dev/null
+++ b/pkg/noun/v1/vortex.c
@@ -0,0 +1,17 @@
+/// @file
+
+#include "pkg/noun/vortex.h"
+#include "pkg/noun/v1/vortex.h"
+
+#include "pkg/noun/v1/allocate.h"
+
+/* u3v_v1_reclaim(): clear ad-hoc persistent caches to reclaim memory.
+*/
+void
+u3v_v1_reclaim(void)
+{
+  //  clear the u3v_wish cache
+  //
+  u3a_v1_lose(u3A_v1->yot);
+  u3A_v1->yot = u3_nul;
+}
diff --git a/pkg/noun/v1/vortex.h b/pkg/noun/v1/vortex.h
new file mode 100644
index 0000000000..84cf6e405c
--- /dev/null
+++ b/pkg/noun/v1/vortex.h
@@ -0,0 +1,22 @@
+/// @file
+
+#ifndef U3_VORTEX_V1_H
+#define U3_VORTEX_V1_H
+
+#include "pkg/noun/allocate.h"
+#include "pkg/noun/v2/vortex.h"
+
+  /**  Aliases.
+  **/
+#     define  u3H_v1       u3H_v2
+#     define  u3A_v1       u3A_v2
+#     define  u3v_v1_home  u3v_v2_home
+
+  /**  Functions.
+  **/
+    /* u3v_v1_reclaim(): clear ad-hoc persistent caches to reclaim memory.
+    */
+      void
+      u3v_v1_reclaim(void);
+
+#endif /* ifndef U3_VORTEX_V1_H */
diff --git a/pkg/noun/v2/allocate.c b/pkg/noun/v2/allocate.c
new file mode 100644
index 0000000000..25cf04a948
--- /dev/null
+++ b/pkg/noun/v2/allocate.c
@@ -0,0 +1,73 @@
+/// @file
+
+#include "pkg/noun/allocate.h"
+#include "pkg/noun/v1/allocate.h"
+#include "pkg/noun/v2/allocate.h"
+
+#include "pkg/noun/v2/hashtable.h"
+#include "log.h"
+#include "pkg/noun/v2/manage.h"
+#include "options.h"
+#include "retrieve.h"
+#include "trace.h"
+#include "vortex.h"
+
+u3a_v2_road* u3a_v2_Road;
+
+u3_noun
+u3a_v2_rewritten_noun(u3_noun som)
+{
+  if ( c3y == u3a_v2_is_cat(som) ) {
+    return som;
+  }
+  u3_post som_p = u3a_v2_rewritten(u3a_v1_to_off(som));
+
+  if ( c3y == u3a_v2_is_pug(som) ) {
+    som_p = u3a_v2_to_pug(som_p);
+  }
+  else {
+    som_p = u3a_v2_to_pom(som_p);
+  }
+
+  return som_p;
+}
+
+/* u3a_v2_mig_rewrite_compact(): rewrite pointers in ad-hoc persistent road structures.
+*/
+void
+u3a_v2_mig_rewrite_compact(void)
+{
+  u3a_v2_rewrite_noun(u3R_v2->ski.gul);
+  u3a_v2_rewrite_noun(u3R_v2->bug.tax);
+  u3a_v2_rewrite_noun(u3R_v2->bug.mer);
+  u3a_v2_rewrite_noun(u3R_v2->pro.don);
+  u3a_v2_rewrite_noun(u3R_v2->pro.day);
+  u3a_v2_rewrite_noun(u3R_v2->pro.trace);
+  u3h_v2_rewrite(u3R_v2->cax.har_p);
+
+  u3R_v2->ski.gul = u3a_v2_rewritten_noun(u3R_v2->ski.gul);
+  u3R_v2->bug.tax = u3a_v2_rewritten_noun(u3R_v2->bug.tax);
+  u3R_v2->bug.mer = u3a_v2_rewritten_noun(u3R_v2->bug.mer);
+  u3R_v2->pro.don = u3a_v2_rewritten_noun(u3R_v2->pro.don);
+  u3R_v2->pro.day = u3a_v2_rewritten_noun(u3R_v2->pro.day);
+  u3R_v2->pro.trace = u3a_v2_rewritten_noun(u3R_v2->pro.trace);
+  u3R_v2->cax.har_p = u3a_v2_rewritten(u3R_v2->cax.har_p);
+}
+
+void
+u3a_v2_rewrite_noun(u3_noun som)
+{
+  if ( c3n == u3a_v2_is_cell(som) ) {
+    return;
+  }
+
+  if ( c3n == u3a_v2_rewrite_ptr(u3a_v1_to_ptr((som))) ) return;
+
+  u3a_v2_cell* cel = (u3a_v2_cell*) u3a_v1_to_ptr(som);
+
+  u3a_v2_rewrite_noun(cel->hed);
+  u3a_v2_rewrite_noun(cel->tel);
+
+  cel->hed = u3a_v2_rewritten_noun(cel->hed);
+  cel->tel = u3a_v2_rewritten_noun(cel->tel);
+}
diff --git a/pkg/noun/v2/allocate.h b/pkg/noun/v2/allocate.h
new file mode 100644
index 0000000000..1f191795fc
--- /dev/null
+++ b/pkg/noun/v2/allocate.h
@@ -0,0 +1,134 @@
+#ifndef U3_ALLOCATE_V2_H
+#define U3_ALLOCATE_V2_H
+
+#include "pkg/noun/allocate.h"
+
+#include "pkg/noun/v2/manage.h"
+#include "options.h"
+
+  /**  Aliases.
+  **/
+#     define u3a_v2_botox        u3a_botox
+#     define u3a_v2_box          u3a_box
+#     define u3a_v2_cell         u3a_cell
+#     define u3a_v2_fbox         u3a_fbox
+#     define u3a_v2_fbox_no      u3a_fbox_no
+#     define u3a_v2_free         u3a_free
+#     define u3a_v2_heap         u3a_heap
+#     define u3a_v2_into         u3a_into
+#     define u3a_v2_is_cat       u3a_is_cat
+#     define u3a_v2_is_cell      u3a_is_cell
+#     define u3a_v2_is_north     u3a_is_north
+#     define u3a_v2_is_pom       u3a_is_pom
+#     define u3a_v2_is_pug       u3a_is_pug
+#     define u3a_v2_lose         u3a_lose
+#     define u3a_v2_malloc       u3a_malloc
+#     define u3a_v2_minimum      u3a_minimum
+#     define u3a_v2_outa         u3a_outa
+#     define u3a_v2_pack_seek    u3a_pack_seek
+#     define u3a_v2_rewrite      u3a_rewrite
+#     define u3a_v2_rewrite_ptr  u3a_rewrite_ptr
+#     define u3a_v2_rewritten    u3a_rewritten
+#     define u3a_v2_to_off       u3a_to_off
+#     define u3a_v2_to_ptr       u3a_to_ptr
+#     define u3a_v2_to_wtr       u3a_to_wtr
+#     define u3a_v2_to_pug       u3a_to_pug
+#     define u3a_v2_to_pom       u3a_to_pom
+#     define u3a_v2_wfree        u3a_wfree
+
+  /**  Data structures.
+  **/
+    /* u3a_v2_road: contiguous allocation and execution context.
+    */
+      typedef struct _u3a_v2_road {
+        u3p(struct _u3a_v2_road) par_p;          //  parent road
+        u3p(struct _u3a_v2_road) kid_p;          //  child road list
+        u3p(struct _u3a_v2_road) nex_p;          //  sibling road
+
+        u3p(c3_w) cap_p;                      //  top of transient region
+        u3p(c3_w) hat_p;                      //  top of durable region
+        u3p(c3_w) mat_p;                      //  bottom of transient region
+        u3p(c3_w) rut_p;                      //  bottom of durable region
+        u3p(c3_w) ear_p;                      //  original cap if kid is live
+
+        c3_w fut_w[32];                       //  futureproof buffer
+
+        struct {                              //  escape buffer
+          union {
+            jmp_buf buf;
+            c3_w buf_w[256];                  //  futureproofing
+          };
+        } esc;
+
+        struct {                              //  miscellaneous config
+          c3_w fag_w;                         //  flag bits
+        } how;                                //
+
+        struct {                                   //  allocation pools
+          u3p(u3a_v2_fbox) fre_p[u3a_v2_fbox_no];  //  heap by node size log
+          u3p(u3a_fbox) cel_p;                //  custom cell allocator
+          c3_w fre_w;                         //  number of free words
+          c3_w max_w;                         //  maximum allocated
+        } all;
+
+        u3a_jets jed;                         //  jet dashboard
+
+        struct {                              // bytecode state
+          u3p(u3h_root) har_p;                // formula->post of bytecode
+        } byc;
+
+        struct {                              //  namespace
+          u3_noun gul;                        //  (list $+(* (unit (unit)))) now
+        } ski;
+
+        struct {                              //  trace stack
+          u3_noun tax;                        //  (list ,*)
+          u3_noun mer;                        //  emergency buffer to release
+        } bug;
+
+        struct {                              //  profile stack
+          c3_d    nox_d;                      //  nock steps
+          c3_d    cel_d;                      //  cell allocations
+          u3_noun don;                        //  (list batt)
+          u3_noun trace;                      //  (list trace)
+          u3_noun day;                        //  doss, only in u3H (moveme)
+        } pro;
+
+        struct {                              //  memoization
+          u3p(u3h_root) har_p;                //  (map (pair term noun) noun)
+        } cax;
+      } u3a_v2_road;
+
+  /**  Globals.
+  **/
+      /// Current road (thread-local).
+      extern u3a_v2_road* u3a_v2_Road;
+#       define u3R_v2  u3a_v2_Road
+
+  /**  Functions.
+  **/
+    /**  Allocation.
+    **/
+      /* Reference and arena control.
+      */
+        /* u3a_v2_mig_rewrite_compact(): rewrite pointers in ad-hoc persistent road structures.
+        */
+          void
+          u3a_v2_mig_rewrite_compact(void);
+
+        /* u3a_v2_rewrite_noun(): rewrite a noun for compaction.
+        */
+          void
+          u3a_v2_rewrite_noun(u3_noun som);
+
+        /* u3a_v2_rewritten(): rewrite a pointer for compaction.
+        */
+          u3_post
+          u3a_v2_rewritten(u3_post som_p);
+
+        /* u3a_v2_rewritten(): rewritten noun pointer for compaction.
+        */
+          u3_noun
+          u3a_v2_rewritten_noun(u3_noun som);
+
+#endif /* ifndef U3_ALLOCATE_V2_H */
diff --git a/pkg/noun/v2/hashtable.c b/pkg/noun/v2/hashtable.c
new file mode 100644
index 0000000000..6963d07fde
--- /dev/null
+++ b/pkg/noun/v2/hashtable.c
@@ -0,0 +1,143 @@
+/// @file
+
+#include "pkg/noun/hashtable.h"
+#include "pkg/noun/v1/hashtable.h"
+#include "pkg/noun/v2/hashtable.h"
+
+#include "pkg/noun/allocate.h"
+#include "pkg/noun/v1/allocate.h"
+#include "pkg/noun/v2/allocate.h"
+
+/* _ch_v2_popcount(): number of bits set in word.  A standard intrinsic.
+**             NB: copy of _ch_v2_popcount in pkg/noun/hashtable.c
+*/
+static c3_w
+_ch_v2_popcount(c3_w num_w)
+{
+  return __builtin_popcount(num_w);
+}
+
+/* _ch_v2_free_buck(): free bucket
+**              NB: copy of _ch_v2_free_buck in pkg/noun/hashtable.c
+*/
+static void
+_ch_v2_free_buck(u3h_v2_buck* hab_u)
+{
+  c3_w i_w;
+
+  for ( i_w = 0; i_w < hab_u->len_w; i_w++ ) {
+    u3z(u3h_v2_slot_to_noun(hab_u->sot_w[i_w]));
+  }
+  u3a_v2_wfree(hab_u);
+}
+
+/* _ch_v2_free_node(): free node.
+*/
+static void
+_ch_v2_free_node(u3h_v2_node* han_u, c3_w lef_w)
+{
+  c3_w len_w = _ch_v2_popcount(han_u->map_w);
+  c3_w i_w;
+
+  lef_w -= 5;
+
+  for ( i_w = 0; i_w < len_w; i_w++ ) {
+    c3_w sot_w = han_u->sot_w[i_w];
+
+    if ( _(u3h_v2_slot_is_noun(sot_w)) ) {
+      u3z(u3h_v2_slot_to_noun(sot_w));
+    }
+    else {
+      //  NB: u3h_v2_slot_to_node()
+      void* hav_v = u3h_v2_slot_to_node(sot_w);
+
+      if ( 0 == lef_w ) {
+        _ch_v2_free_buck(hav_v);
+      } else {
+        _ch_v2_free_node(hav_v, lef_w);
+      }
+    }
+  }
+  u3a_v2_wfree(han_u);
+}
+
+/* _ch_v2_rewrite_buck(): rewrite buck for compaction.
+*/
+void
+_ch_v2_rewrite_buck(u3h_v2_buck* hab_u)
+{
+  if ( c3n == u3a_v2_rewrite_ptr(hab_u) ) return;
+  c3_w i_w;
+
+  for ( i_w = 0; i_w < hab_u->len_w; i_w++ ) {
+    u3_noun som = u3h_v2_slot_to_noun(hab_u->sot_w[i_w]);
+    hab_u->sot_w[i_w] = u3h_v2_noun_to_slot(u3a_v2_rewritten_noun(som));
+    u3a_v2_rewrite_noun(som);
+  }
+}
+
+/* _ch_v2_rewrite_node(): rewrite node for compaction.
+*/
+void
+_ch_v2_rewrite_node(u3h_v2_node* han_u, c3_w lef_w)
+{
+  if ( c3n == u3a_v2_rewrite_ptr(han_u) ) return;
+
+  c3_w len_w = _ch_v2_popcount(han_u->map_w);
+  c3_w i_w;
+
+  lef_w -= 5;
+
+  for ( i_w = 0; i_w < len_w; i_w++ ) {
+    c3_w sot_w = han_u->sot_w[i_w];
+
+    if ( _(u3h_v2_slot_is_noun(sot_w)) ) {
+      u3_noun kev = u3h_v2_slot_to_noun(sot_w);
+      han_u->sot_w[i_w] = u3h_v2_noun_to_slot(u3a_v2_rewritten_noun(kev));
+
+      u3a_v2_rewrite_noun(kev);
+    }
+    else {
+      void* hav_v = u3h_v1_slot_to_node(sot_w);
+      u3h_v2_node* nod_u = u3to(u3h_v2_node, u3a_v2_rewritten(u3of(u3h_v2_node,hav_v)));
+
+      han_u->sot_w[i_w] = u3h_v2_node_to_slot(nod_u);
+
+      if ( 0 == lef_w ) {
+        _ch_v2_rewrite_buck(hav_v);
+      } else {
+        _ch_v2_rewrite_node(hav_v, lef_w);
+      }
+    }
+  }
+}
+
+/* u3h_v2_rewrite(): rewrite pointers during compaction.
+*/
+void
+u3h_v2_rewrite(u3p(u3h_v2_root) har_p)
+{
+  u3h_v2_root* har_u = u3to(u3h_v2_root, har_p);
+  c3_w        i_w;
+
+  if ( c3n == u3a_v2_rewrite_ptr(har_u) ) return;
+
+  for ( i_w = 0; i_w < 64; i_w++ ) {
+    c3_w sot_w = har_u->sot_w[i_w];
+
+    if ( _(u3h_v2_slot_is_noun(sot_w)) ) {
+      u3_noun kev = u3h_v2_slot_to_noun(sot_w);
+      har_u->sot_w[i_w] = u3h_v2_noun_to_slot(u3a_v2_rewritten_noun(kev));
+
+      u3a_v2_rewrite_noun(kev);
+    }
+    else if ( _(u3h_v2_slot_is_node(sot_w)) ) {
+      u3h_v2_node* han_u = (u3h_v2_node*) u3h_v1_slot_to_node(sot_w);
+      u3h_v2_node* nod_u = u3to(u3h_v2_node, u3a_v2_rewritten(u3of(u3h_v2_node,han_u)));
+
+      har_u->sot_w[i_w] = u3h_v2_node_to_slot(nod_u);
+
+      _ch_v2_rewrite_node(han_u, 25);
+    }
+  }
+}
diff --git a/pkg/noun/v2/hashtable.h b/pkg/noun/v2/hashtable.h
new file mode 100644
index 0000000000..09025fc19f
--- /dev/null
+++ b/pkg/noun/v2/hashtable.h
@@ -0,0 +1,42 @@
+#ifndef U3_HASHTABLE_V2_H
+#define U3_HASHTABLE_V2_H
+
+#define u3h_v2_buck          u3h_buck
+#define u3h_v2_free          u3h_free
+#define u3h_v2_new           u3h_new
+#define u3h_v2_node          u3h_node
+#define u3h_v2_noun_to_slot  u3h_noun_to_slot
+#define u3h_v2_root          u3h_root
+#define u3h_v2_slot_is_node  u3h_slot_is_node
+#define u3h_v2_slot_is_noun  u3h_slot_is_noun
+#define u3h_v2_slot_to_noun  u3h_slot_to_noun
+#define u3h_v2_walk          u3h_walk
+#define u3h_v2_walk_with     u3h_walk_with
+
+#include "pkg/noun/hashtable.h"
+
+#include "c3.h"
+#include "types.h"
+
+  /**  Data structures.
+  **/
+
+    /**  HAMT macros.
+    ***
+    ***  Coordinate with u3_noun definition!
+    **/
+      /* u3h_v2_slot_to_node(): slot to node pointer
+      ** u3h_v2_node_to_slot(): node pointer to slot
+      */
+#     define  u3h_v2_slot_to_node(sot)  (u3a_v2_into(((sot) & 0x3fffffff) << u3a_vits))
+#     define  u3h_v2_node_to_slot(ptr)  ((u3a_v2_outa((ptr)) >> u3a_vits) | 0x40000000)
+
+    /**  Functions.
+    ***
+    **/
+      /* u3h_v2_rewrite(): rewrite hashtable for compaction.
+      */
+        void
+        u3h_v2_rewrite(u3p(u3h_root) har_p);
+
+#endif /* U3_HASHTABLE_V2_H */
diff --git a/pkg/noun/v2/jets.c b/pkg/noun/v2/jets.c
new file mode 100644
index 0000000000..c22ea97f3b
--- /dev/null
+++ b/pkg/noun/v2/jets.c
@@ -0,0 +1,54 @@
+/// @file
+
+#include "pkg/noun/vortex.h"
+
+#include "pkg/noun/jets.h"
+#include "pkg/noun/v2/jets.h"
+
+#include "pkg/noun/v2/allocate.h"
+#include "pkg/noun/v2/hashtable.h"
+#include "pkg/noun/v2/vortex.h"
+
+#include "pkg/noun/v3/hashtable.h"
+#include "pkg/noun/v3/jets.h"
+
+/* u3j_v2_reclaim(): clear ad-hoc persistent caches to reclaim memory.
+*/
+void
+u3j_v2_reclaim(void)
+{
+  //  set globals (required for aliased functions)
+  u3H = (u3v_home*) u3H_v2;
+  u3R = (u3a_road*) u3R_v2;
+
+  //  clear the jet hank cache
+  //
+  u3h_v3_walk(u3R->jed.han_p, u3j_v3_free_hank);
+  u3h_v3_free(u3R->jed.han_p);
+  u3R->jed.han_p = u3h_v3_new();
+}
+
+/* u3j_v2_mig_rewrite_compact(): rewrite jet state for compaction.
+ *
+ * NB: u3R_v2->jed.han_p *must* be cleared (currently via u3j_v2_reclaim above)
+ * since it contains hanks which are not nouns but have loom pointers.
+ * Alternately, rewrite the entries with u3h_v2_walk, using u3j_v2_mark as a
+ * template for how to walk.  There's an untested attempt at this in git
+ * history at e8a307a.
+*/
+void
+u3j_v2_mig_rewrite_compact()
+{
+  u3h_v2_rewrite(u3R_v2->jed.war_p);
+  u3h_v2_rewrite(u3R_v2->jed.cod_p);
+  u3h_v2_rewrite(u3R_v2->jed.han_p);
+  u3h_v2_rewrite(u3R_v2->jed.bas_p);
+
+  u3h_v2_rewrite(u3R_v2->jed.hot_p);
+  u3R_v2->jed.hot_p = u3a_v2_rewritten(u3R_v2->jed.hot_p);
+
+  u3R_v2->jed.war_p = u3a_v2_rewritten(u3R_v2->jed.war_p);
+  u3R_v2->jed.cod_p = u3a_v2_rewritten(u3R_v2->jed.cod_p);
+  u3R_v2->jed.han_p = u3a_v2_rewritten(u3R_v2->jed.han_p);
+  u3R_v2->jed.bas_p = u3a_v2_rewritten(u3R_v2->jed.bas_p);
+}
diff --git a/pkg/noun/v2/jets.h b/pkg/noun/v2/jets.h
new file mode 100644
index 0000000000..526046905d
--- /dev/null
+++ b/pkg/noun/v2/jets.h
@@ -0,0 +1,35 @@
+/// @file
+
+#ifndef U3_JETS_V2_H
+#define U3_JETS_V2_H
+
+#include "pkg/noun/allocate.h"
+#include "pkg/noun/jets.h"
+
+
+  /**  Aliases.
+  **/
+#     define  u3j_v2_core       u3j_core
+#     define  u3j_v2_fink       u3j_fink
+#     define  u3j_v2_fist       u3j_fist
+#     define  u3j_v2_hank       u3j_hank
+#     define  u3j_v2_free_hank  u3j_free_hank
+#     define  u3j_v2_harm       u3j_harm
+#     define  u3j_v2_rite       u3j_rite
+#     define  u3j_v2_site       u3j_site
+#     define  u3j_v2_rite_lose  u3j_rite_lose
+#     define  u3j_v2_site_lose  u3j_site_lose
+
+  /**  Functions.
+  **/
+    /* u3j_v2_reclaim(): clear ad-hoc persistent caches to reclaim memory.
+    */
+      void
+      u3j_v2_reclaim(void);
+
+    /* u3j_v2_mig_rewrite_compact(): rewrite jet state for compaction.
+    */
+      void
+      u3j_v2_mig_rewrite_compact();
+
+#endif /* ifndef U3_JETS_V2_H */
diff --git a/pkg/noun/v2/manage.c b/pkg/noun/v2/manage.c
new file mode 100644
index 0000000000..113ecc2b6b
--- /dev/null
+++ b/pkg/noun/v2/manage.c
@@ -0,0 +1,174 @@
+/// @file
+
+#include "pkg/noun/v2/manage.h"
+
+#include "pkg/noun/v1/allocate.h"
+#include "pkg/noun/v2/allocate.h"
+#include "pkg/noun/v2/hashtable.h"
+#include "pkg/noun/v2/jets.h"
+#include "pkg/noun/v2/nock.h"
+#include "pkg/noun/v2/options.h"
+#include "pkg/noun/vortex.h"
+#include "pkg/noun/v1/vortex.h"
+#include "pkg/noun/v2/vortex.h"
+
+/* _cm_pack_rewrite(): trace through arena, rewriting pointers.
+*/
+static void
+_cm_pack_rewrite(void)
+{
+  u3v_v2_mig_rewrite_compact();
+  u3j_v2_mig_rewrite_compact();
+  u3n_v2_mig_rewrite_compact();
+  u3a_v2_mig_rewrite_compact();
+}
+
+static void
+_migrate_reclaim()
+{
+  //  XX update this and similar printfs
+  fprintf(stderr, "loom: migration reclaim\r\n");
+  u3m_v1_reclaim();
+}
+
+static void
+_migrate_seek(const u3a_v2_road *rod_u)
+{
+  /*
+    very much like u3a_v2_pack_seek with the following changes:
+    - there is no need to account for free space as |pack is performed before
+      the migration
+    - odd sized boxes will be padded by one word to achieve an even size
+    - rut will be moved from one word ahead of u3_Loom to two words ahead
+  */
+  c3_w *    box_w = u3a_v2_into(rod_u->rut_p);
+  c3_w *    end_w = u3a_v2_into(rod_u->hat_p);
+  u3_post   new_p = (rod_u->rut_p + 1 + c3_wiseof(u3a_v2_box));
+  u3a_v2_box * box_u = (void *)box_w;
+
+  fprintf(stderr, "loom: migration seek\r\n");
+
+  for (; box_w < end_w
+         ; box_w += box_u->siz_w
+         , box_u = (void*)box_w)
+    {
+      if (!box_u->use_w)
+        continue;
+      u3_assert(box_u->siz_w);
+      u3_assert(box_u->use_w);
+      box_w[box_u->siz_w - 1] = new_p;
+      new_p = c3_align(new_p + box_u->siz_w, 2, C3_ALGHI);
+    }
+}
+
+static void
+_migrate_rewrite()
+{
+  fprintf(stderr, "loom: migration rewrite\r\n");
+
+  _cm_pack_rewrite();
+}
+
+static void
+_migrate_move(u3a_v2_road *rod_u)
+{
+  fprintf(stderr, "loom: migration move\r\n");
+
+  c3_z hiz_z = u3a_v2_heap(rod_u) * sizeof(c3_w);
+
+  /* calculate required shift distance to prevent write head overlapping read head */
+  c3_w  off_w = 1;  /* at least 1 word because u3R_v1->rut_p migrates from 1 to 2 */
+  for (u3a_v2_box *box_u = u3a_v2_into(rod_u->rut_p)
+         ; (void *)box_u < u3a_v2_into(rod_u->hat_p)
+         ; box_u = (void *)((c3_w *)box_u + box_u->siz_w))
+    off_w += box_u->siz_w & 1; /* odd-sized boxes are padded by one word */
+
+  /* shift */
+  memmove(u3a_v2_into(u3H_v2->rod_u.rut_p + off_w),
+          u3a_v2_into(u3H_v2->rod_u.rut_p),
+          hiz_z);
+  /* manually zero the former rut */
+  *(c3_w *)u3a_v2_into(rod_u->rut_p) = 0;
+
+  /* relocate boxes to DWORD-aligned addresses stored in trailing size word */
+  c3_w *box_w = u3a_v2_into(rod_u->rut_p + off_w);
+  c3_w *end_w = u3a_v2_into(rod_u->hat_p + off_w);
+  u3a_v2_box *old_u = (void *)box_w;
+  c3_w siz_w = old_u->siz_w;
+  u3p(c3_w) new_p = rod_u->rut_p + 1 + c3_wiseof(u3a_v2_box);
+  c3_w *new_w;
+
+  for (; box_w < end_w
+         ; box_w += siz_w
+         , old_u = (void *)box_w
+         , siz_w = old_u->siz_w) {
+    old_u->use_w &= 0x7fffffff;
+
+    if (!old_u->use_w)
+      continue;
+
+    new_w = (void *)u3a_v2_botox(u3a_v2_into(new_p));
+    u3_assert(box_w[siz_w - 1] == new_p);
+    u3_assert(new_w <= box_w);
+
+    c3_w i_w;
+    for (i_w = 0; i_w < siz_w - 1; i_w++)
+      new_w[i_w] = box_w[i_w];
+
+    if (siz_w & 1) {
+      new_w[i_w++] = 0;         /* pad odd sized boxes */
+      new_w[i_w++] = siz_w + 1; /* restore trailing size word */
+      new_w[0] = siz_w + 1;     /* and the leading size word */
+    }
+    else {
+      new_w[i_w++] = siz_w;
+    }
+
+    new_p += i_w;
+  }
+
+  /* restore proper heap state */
+  rod_u->rut_p = 2;
+  rod_u->hat_p = new_p - c3_wiseof(u3a_v2_box);
+
+  /* like |pack, clear the free lists and cell allocator */
+  for (c3_w i_w = 0; i_w < u3a_v2_fbox_no; i_w++)
+    u3R_v1->all.fre_p[i_w] = 0;
+
+  u3R_v1->all.fre_w = 0;
+  u3R_v1->all.cel_p = 0;
+}
+
+
+/* u3m_v2_migrate: perform loom migration if necessary.
+*/
+void
+u3m_v2_migrate()
+{
+  c3_w len_w = u3C_v2.wor_i - 1;
+  c3_w ver_w = *(u3_Loom + len_w);
+
+  u3_assert( U3V_VER1 == ver_w );
+
+  c3_w* mem_w = u3_Loom + 1;
+  c3_w  siz_w = c3_wiseof(u3v_v1_home);
+  c3_w* mat_w = (mem_w + len_w) - siz_w;
+
+  u3H_v1 = (void *)mat_w;
+  u3R_v1 = &u3H_v1->rod_u;
+
+  u3R_v1->cap_p = u3R_v1->mat_p = u3a_v1_outa(u3H_v1);
+
+  fprintf(stderr, "loom: pointer compression migration running...\r\n");
+
+  /* perform the migration in a pattern similar to |pack */
+  _migrate_reclaim();
+  _migrate_seek(&u3H_v1->rod_u);
+  _migrate_rewrite();
+  _migrate_move(&u3H_v1->rod_u);
+
+  /* finally update the version and commit to disk */
+  u3H_v1->ver_w = U3V_VER2;
+
+  fprintf(stderr, "loom: pointer compression migration done\r\n");
+}
diff --git a/pkg/noun/v2/manage.h b/pkg/noun/v2/manage.h
new file mode 100644
index 0000000000..1d03b97809
--- /dev/null
+++ b/pkg/noun/v2/manage.h
@@ -0,0 +1,13 @@
+/// @file
+
+#ifndef U3_MANAGE_V2_H
+#define U3_MANAGE_V2_H
+
+    /**  System management.
+    **/
+      /* u3m_v2_migrate: perform pointer compression loom migration if necessary.
+      */
+        void
+        u3m_v2_migrate();
+
+#endif /* ifndef U3_MANAGE_V2_H */
diff --git a/pkg/noun/v2/nock.c b/pkg/noun/v2/nock.c
new file mode 100644
index 0000000000..e6ff116ce1
--- /dev/null
+++ b/pkg/noun/v2/nock.c
@@ -0,0 +1,92 @@
+/// @file
+
+#include "pkg/noun/v2/nock.h"
+
+#include "pkg/noun/vortex.h"
+
+#include "pkg/noun/v2/allocate.h"
+#include "pkg/noun/v2/hashtable.h"
+#include "pkg/noun/v2/vortex.h"
+
+#include "pkg/noun/v3/hashtable.h"
+
+/* u3n_v2_reclaim(): clear ad-hoc persistent caches to reclaim memory.
+*/
+void
+u3n_v2_reclaim(void)
+{
+  //  set globals (required for aliased functions)
+  u3H = (u3v_home*) u3H_v2;
+  u3R = (u3a_road*) u3R_v2;
+
+  //  clear the bytecode cache
+  u3n_v2_free();
+  u3R->byc.har_p = u3h_v2_new();
+}
+
+/* _cn_v2_prog_free(): free memory retained by program pog_u
+*/
+static void
+_cn_v2_prog_free(u3n_v2_prog* pog_u)
+{
+  // fix up pointers for loom portability
+  pog_u->byc_u.ops_y = (c3_y*) ((void*) pog_u) + sizeof(u3n_v2_prog);
+  pog_u->lit_u.non   = (u3_noun*) (pog_u->byc_u.ops_y + pog_u->byc_u.len_w);
+  pog_u->mem_u.sot_u = (u3n_v2_memo*) (pog_u->lit_u.non + pog_u->lit_u.len_w);
+  pog_u->cal_u.sit_u = (u3j_v2_site*) (pog_u->mem_u.sot_u + pog_u->mem_u.len_w);
+  pog_u->reg_u.rit_u = (u3j_v2_rite*) (pog_u->cal_u.sit_u + pog_u->cal_u.len_w);
+
+  c3_w dex_w;
+  for (dex_w = 0; dex_w < pog_u->lit_u.len_w; ++dex_w) {
+    u3a_v2_lose(pog_u->lit_u.non[dex_w]);
+  }
+  for (dex_w = 0; dex_w < pog_u->mem_u.len_w; ++dex_w) {
+    u3a_v2_lose(pog_u->mem_u.sot_u[dex_w].key);
+  }
+  for (dex_w = 0; dex_w < pog_u->cal_u.len_w; ++dex_w) {
+    u3j_v2_site_lose(&(pog_u->cal_u.sit_u[dex_w]));
+  }
+  for (dex_w = 0; dex_w < pog_u->reg_u.len_w; ++dex_w) {
+    u3j_v2_rite_lose(&(pog_u->reg_u.rit_u[dex_w]));
+  }
+  u3a_v2_free(pog_u);
+}
+
+/* _n_v2_feb(): u3h_v2_walk helper for u3n_v2_free
+ */
+static void
+_n_v2_feb(u3_noun kev)
+{
+  u3a_v2_cell *cel_u = (u3a_v2_cell*) u3a_v2_to_ptr(kev);
+  _cn_v2_prog_free(u3to(u3n_v2_prog, cel_u->tel));
+}
+
+/* u3n_v2_free(): free bytecode cache
+ */
+void
+u3n_v2_free()
+{
+  u3p(u3h_v2_root) har_p = u3R_v2->byc.har_p;
+  u3h_v2_walk(har_p, _n_v2_feb);
+  u3h_v2_free(har_p);
+}
+
+/* u3n_v2_mig_rewrite_compact(): rewrite the bytecode cache for compaction.
+ *
+ * NB: u3R_v2->byc.har_p *must* be cleared (currently via u3n_v2_reclaim above),
+ * since it contains things that look like nouns but aren't.
+ * Specifically, it contains "cells" where the tail is a
+ * pointer to a u3a_v2_malloc'ed block that contains loom pointers.
+ *
+ * You should be able to walk this with u3h_v2_walk and rewrite the
+ * pointers, but you need to be careful to handle that u3a_v2_malloc
+ * pointers can't be turned into a box by stepping back two words. You
+ * must step back one word to get the padding, step then step back that
+ * many more words (plus one?).
+ */
+void
+u3n_v2_mig_rewrite_compact()
+{
+  u3h_v2_rewrite(u3R_v2->byc.har_p);
+  u3R_v2->byc.har_p = u3a_v2_rewritten(u3R_v2->byc.har_p);
+}
diff --git a/pkg/noun/v2/nock.h b/pkg/noun/v2/nock.h
new file mode 100644
index 0000000000..e7d44aee08
--- /dev/null
+++ b/pkg/noun/v2/nock.h
@@ -0,0 +1,64 @@
+/// @file
+
+#ifndef U3_NOCK_V2_H
+#define U3_NOCK_V2_H
+
+#include "pkg/noun/v3/nock.h"
+
+#include "pkg/noun/v2/jets.h"
+
+#include "types.h"
+
+  /** Data structures.
+  **/
+    /* u3n_memo: %memo hint space
+     */
+    typedef struct {
+      c3_l    sip_l;
+      u3_noun key;
+    } u3n_v2_memo;
+
+  /* u3n_v2_prog: program compiled from nock
+   */
+  typedef struct _u3n_v2_prog {
+    struct {
+      c3_o      own_o;                // program owns ops_y?
+      c3_w      len_w;                // length of bytecode (bytes)
+      c3_y*     ops_y;                // actual array of bytes
+    } byc_u;                          // bytecode
+    struct {
+      c3_w      len_w;                // number of literals
+      u3_noun*  non;                  // array of literals
+    } lit_u;                          // literals
+    struct {
+      c3_w      len_w;                // number of memo slots
+      u3n_v2_memo* sot_u;             // array of memo slots
+    } mem_u;                          // memo slot data
+    struct {
+      c3_w      len_w;                // number of calls sites
+      u3j_v2_site* sit_u;             // array of sites
+    } cal_u;                          // call site data
+    struct {
+      c3_w      len_w;                // number of registration sites
+      u3j_v2_rite* rit_u;             // array of sites
+    } reg_u;                          // registration site data
+  } u3n_v2_prog;
+
+  /**  Functions.
+  **/
+    /* u3n_v2_reclaim(): clear ad-hoc persistent caches to reclaim memory.
+    */
+      void
+      u3n_v2_reclaim(void);
+
+    /* u3n_v2_free(): free bytecode cache.
+     */
+      void
+      u3n_v2_free(void);
+
+    /* u3n_v2_mig_rewrite_compact(): rewrite bytecode cache for compaction.
+     */
+      void
+      u3n_v2_mig_rewrite_compact();
+
+#endif /* ifndef U3_NOCK_V2_H */
diff --git a/pkg/noun/v2/options.h b/pkg/noun/v2/options.h
new file mode 100644
index 0000000000..4af573f20d
--- /dev/null
+++ b/pkg/noun/v2/options.h
@@ -0,0 +1,14 @@
+/// @file
+
+#ifndef U3_OPTIONS_V2_H
+#define U3_OPTIONS_V2_H
+
+#include "pkg/noun/options.h"
+
+  /** Globals.
+  **/
+    /* u3_Config / u3C: global memory control.
+    */
+#     define u3C_v2  u3C
+
+#endif /* ifndef U3_OPTIONS_H */
diff --git a/pkg/noun/v2/vortex.c b/pkg/noun/v2/vortex.c
new file mode 100644
index 0000000000..b22dfaed4d
--- /dev/null
+++ b/pkg/noun/v2/vortex.c
@@ -0,0 +1,25 @@
+/// @file
+
+#include "pkg/noun/vortex.h"
+#include "pkg/noun/v2/vortex.h"
+
+#include "pkg/noun/v2/allocate.h"
+
+u3v_v2_home* u3v_v2_Home;
+
+/* u3v_v2_mig_rewrite_compact(): rewrite arvo kernel for compaction.
+*/
+void
+u3v_v2_mig_rewrite_compact()
+{
+  u3v_v2_arvo* arv_u = &(u3H_v2->arv_u);
+
+  u3a_v2_rewrite_noun(arv_u->roc);
+  u3a_v2_rewrite_noun(arv_u->now);
+  u3a_v2_rewrite_noun(arv_u->yot);
+
+  arv_u->roc = u3a_v2_rewritten_noun(arv_u->roc);
+  arv_u->now = u3a_v2_rewritten_noun(arv_u->now);
+  arv_u->yot = u3a_v2_rewritten_noun(arv_u->yot);
+}
+
diff --git a/pkg/noun/v2/vortex.h b/pkg/noun/v2/vortex.h
new file mode 100644
index 0000000000..ee8a2f861e
--- /dev/null
+++ b/pkg/noun/v2/vortex.h
@@ -0,0 +1,40 @@
+/// @file
+
+#ifndef U3_VORTEX_V2_H
+#define U3_VORTEX_V2_H
+
+#include "pkg/noun/vortex.h"
+
+#include "pkg/noun/v2/allocate.h"
+#include "pkg/noun/version.h"
+
+  /**  Aliases.
+  **/
+#     define     u3v_v2_arvo  u3v_arvo
+
+  /**  Data structures.
+  **/
+    /* u3v_v2_home: all internal (within image) state.
+    **       NB: version must be last for discriminability in north road
+    */
+      typedef struct _u3v_v2_home {
+        u3a_v2_road    rod_u;                //  storage state
+        u3v_v2_arvo    arv_u;                //  arvo state
+        u3v_version    ver_w;                //  version number
+      } u3v_v2_home;
+
+  /**  Globals.
+  **/
+      /// Arvo internal state.
+      extern u3v_v2_home* u3v_v2_Home;
+#       define u3H_v2  u3v_v2_Home
+#       define u3A_v2  (&(u3v_v2_Home->arv_u))
+
+  /**  Functions.
+  **/
+    /* u3v_v2_mig_rewrite_compact(): rewrite arvo kernel for compaction.
+    */
+      void
+      u3v_v2_mig_rewrite_compact();
+
+#endif /* ifndef U3_VORTEX_V2_H */
diff --git a/pkg/noun/v3/allocate.h b/pkg/noun/v3/allocate.h
new file mode 100644
index 0000000000..83db4a51b9
--- /dev/null
+++ b/pkg/noun/v3/allocate.h
@@ -0,0 +1,18 @@
+#ifndef U3_ALLOCATE_V3_H
+#define U3_ALLOCATE_V3_H
+
+#include "pkg/noun/allocate.h"
+
+#include "pkg/noun/v3/manage.h"
+#include "options.h"
+
+  /**  Aliases.
+  **/
+#     define u3R_v3              u3a_Road
+#     define u3a_v3_balign       u3a_balign
+#     define u3a_v3_road         u3a_road
+#     define u3a_v3_ream         u3a_ream
+#     define u3a_v3_walign       u3a_walign
+#     define u3a_v3_walloc       u3a_walloc
+
+#endif /* ifndef U3_ALLOCATE_V3_H */
diff --git a/pkg/noun/v3/hashtable.c b/pkg/noun/v3/hashtable.c
new file mode 100644
index 0000000000..b17d7b6e78
--- /dev/null
+++ b/pkg/noun/v3/hashtable.c
@@ -0,0 +1,33 @@
+/// @file
+
+#include "pkg/noun/v3/hashtable.h"
+
+#include "pkg/noun/allocate.h"
+#include "pkg/noun/vortex.h"
+
+#include "pkg/noun/v3/allocate.h"
+#include "pkg/noun/v3/vortex.h"
+
+/* u3h_v3_new_cache(): create hashtable with bounded size.
+*/
+u3p(u3h_v3_root)
+u3h_v3_new_cache(c3_w max_w)
+{
+  //  set globals (required for aliased functions)
+  u3H = (u3v_home*) u3H_v3;
+  u3R = (u3a_road*) u3R_v3;
+
+  u3h_v3_root*     har_u = u3a_v3_walloc(c3_wiseof(u3h_v3_root));
+  u3p(u3h_v3_root) har_p = u3of(u3h_v3_root, har_u);
+  c3_w        i_w;
+
+  har_u->max_w       = max_w;
+  har_u->use_w       = 0;
+  har_u->arm_u.mug_w = 0;
+  har_u->arm_u.inx_w = 0;
+
+  for ( i_w = 0; i_w < 64; i_w++ ) {
+    har_u->sot_w[i_w] = 0;
+  }
+  return har_p;
+}
diff --git a/pkg/noun/v3/hashtable.h b/pkg/noun/v3/hashtable.h
new file mode 100644
index 0000000000..14e0e47753
--- /dev/null
+++ b/pkg/noun/v3/hashtable.h
@@ -0,0 +1,18 @@
+#ifndef U3_HASHTABLE_V3_H
+#define U3_HASHTABLE_V3_H
+
+#define u3h_v3_free          u3h_free
+#define u3h_v3_new           u3h_new
+#define u3h_v3_root          u3h_root
+#define u3h_v3_walk          u3h_walk
+
+#include "pkg/noun/hashtable.h"
+
+  /**  Functions.
+  **/
+    /* u3h_v3_new_cache(): create hashtable with bounded size.
+    */
+      u3p(u3h_v3_root)
+      u3h_v3_new_cache(c3_w clk_w);
+
+#endif /* U3_HASHTABLE_V3_H */
diff --git a/pkg/noun/v3/jets.h b/pkg/noun/v3/jets.h
new file mode 100644
index 0000000000..a0fe54f9d7
--- /dev/null
+++ b/pkg/noun/v3/jets.h
@@ -0,0 +1,12 @@
+/// @file
+
+#ifndef U3_JETS_V3_H
+#define U3_JETS_V3_H
+
+#include "pkg/noun/jets.h"
+
+  /**  Aliases.
+  **/
+#     define  u3j_v3_free_hank  u3j_free_hank
+
+#endif /* ifndef U3_JETS_V3_H */
diff --git a/pkg/noun/v3/manage.c b/pkg/noun/v3/manage.c
new file mode 100644
index 0000000000..9eb8a96cdb
--- /dev/null
+++ b/pkg/noun/v3/manage.c
@@ -0,0 +1,110 @@
+/// @file
+
+#include "pkg/noun/v3/manage.h"
+
+#include "pkg/noun/v2/jets.h"
+#include "pkg/noun/v2/nock.h"
+#include "pkg/noun/v2/vortex.h"
+
+#include "pkg/noun/v3/allocate.h"
+#include "pkg/noun/v3/hashtable.h"
+#include "pkg/noun/version.h"
+#include "pkg/noun/v3/vortex.h"
+#include <v2/allocate.h>
+
+/* u3m_v3_migrate: perform loom migration if necessary.
+*/
+void
+u3m_v3_migrate()
+{
+  fprintf(stderr, "loom: memoization migration running...\r\n");
+
+
+  c3_w ver_w = *(u3_Loom + u3C.wor_i - 1);
+  c3_w *mem_w = u3_Loom + u3a_v3_walign;
+  c3_w  len_w = u3C.wor_i - u3a_v3_walign;
+  c3_w  suz_w = c3_wiseof(u3v_v2_home);
+  c3_w *mut_w = c3_align(mem_w + len_w - suz_w, u3a_v3_balign, C3_ALGLO);
+
+  //  old road
+  u3v_v2_home* hum_u = (u3v_v2_home*)mut_w;
+  u3a_v2_road* rud_u = &hum_u->rod_u;
+  size_t ruz_t = sizeof(u3a_v2_road);
+
+  //  set v2 globals
+  u3H_v2 = (void *)mut_w;
+  u3R_v2 = &u3H_v2->rod_u;
+  u3R_v2->cap_p = u3R_v2->mat_p = u3a_v2_outa(u3H_v2);
+
+  //  free bytecode caches in old road
+  u3j_v2_reclaim();
+  u3n_v2_reclaim();
+
+  //  new home, new road
+  u3v_v3_home hom_u = {0};
+  u3a_v3_road rod_u = {0};
+
+  //  copy members, one-by-one, from old road to new road
+  rod_u.par_p = rud_u->par_p;
+  rod_u.kid_p = rud_u->kid_p;
+  rod_u.nex_p = rud_u->nex_p;
+
+  rod_u.cap_p = rud_u->cap_p;
+  rod_u.hat_p = rud_u->hat_p;
+  rod_u.mat_p = rud_u->mat_p;
+  rod_u.rut_p = rud_u->rut_p;
+  rod_u.ear_p = rud_u->ear_p;
+
+  //  no need to zero-out fut_w
+  //  no need to do anything with esc
+
+  rod_u.how.fag_w = rud_u->how.fag_w;
+
+  memcpy(rod_u.all.fre_p, rud_u->all.fre_p, sizeof(rud_u->all.fre_p));
+  rod_u.all.cel_p = rud_u->all.cel_p;
+  rod_u.all.fre_w = rud_u->all.fre_w;
+  rod_u.all.max_w = rud_u->all.max_w;
+
+  rod_u.jed.hot_p = rud_u->jed.hot_p;
+  rod_u.jed.war_p = rud_u->jed.war_p;
+  rod_u.jed.cod_p = rud_u->jed.cod_p;
+  rod_u.jed.han_p = rud_u->jed.han_p;
+  rod_u.jed.bas_p = rud_u->jed.bas_p;
+
+  rod_u.byc.har_p = rud_u->byc.har_p;
+
+  rod_u.ski.gul = rud_u->ski.gul;
+
+  rod_u.bug.tax = rud_u->bug.tax;
+  rod_u.bug.mer = rud_u->bug.mer;
+
+  rod_u.pro.nox_d = rud_u->pro.nox_d;
+  rod_u.pro.cel_d = rud_u->pro.cel_d;
+  rod_u.pro.don   = rud_u->pro.don;
+  rod_u.pro.trace = rud_u->pro.trace;
+  rod_u.pro.day   = rud_u->pro.day;
+
+  rod_u.cax.har_p = rud_u->cax.har_p;
+
+  //  prepare the new home, update the version
+  hom_u.arv_u = hum_u->arv_u;
+  hom_u.rod_u = rod_u;
+
+  //  place the new home over the old one
+  c3_w  siz_w = c3_wiseof(u3v_v3_home);
+  c3_w *mat_w = c3_align(mem_w + len_w - siz_w, u3a_v3_balign, C3_ALGLO);
+  memcpy(mat_w, &hom_u, sizeof(u3v_v3_home));
+
+  //  set globals
+  u3H_v3 = (void*)mat_w;
+  u3R_v3 = &u3H_v3->rod_u;
+  u3H_v3->ver_w = U3V_VER3;
+
+  //  recalculate free lists
+  u3a_v3_ream();
+
+  //  initialize persistent cache
+  u3R_v3->cax.per_p = u3h_v3_new_cache(u3C.per_w);
+
+  fprintf(stderr, "loom: memoization migration done\r\n");
+}
diff --git a/pkg/noun/v3/manage.h b/pkg/noun/v3/manage.h
new file mode 100644
index 0000000000..5745a6316b
--- /dev/null
+++ b/pkg/noun/v3/manage.h
@@ -0,0 +1,13 @@
+/// @file
+
+#ifndef U3_MANAGE_V3_H
+#define U3_MANAGE_V3_H
+
+    /** System management.
+    **/
+      /* u3m_v3_migrate: perform memoization loom migration if necessary.
+      */
+        void
+        u3m_v3_migrate();
+
+#endif /* ifndef U3_MANAGE_V3_H */
diff --git a/pkg/noun/v3/nock.h b/pkg/noun/v3/nock.h
new file mode 100644
index 0000000000..a7b208ba99
--- /dev/null
+++ b/pkg/noun/v3/nock.h
@@ -0,0 +1,17 @@
+/// @file
+
+#ifndef U3_NOCK_V3_H
+#define U3_NOCK_V3_H
+
+#include "pkg/noun/nock.h"
+
+#include "types.h"
+
+  /**  Aliases.
+  **/
+#     define  u3n_v3_free     u3n_free
+#     define  u3n_v3_memo     u3n_memo
+#     define  u3n_v3_prog     u3n_prog
+#     define  u3n_v3_reclaim  u3n_reclaim
+
+#endif /* ifndef U3_NOCK_V3_H */
diff --git a/pkg/noun/v3/vortex.h b/pkg/noun/v3/vortex.h
new file mode 100644
index 0000000000..d47ac19654
--- /dev/null
+++ b/pkg/noun/v3/vortex.h
@@ -0,0 +1,19 @@
+/// @file
+
+#ifndef U3_VORTEX_V3_H
+#define U3_VORTEX_V3_H
+
+#include "pkg/noun/vortex.h"
+
+#include "pkg/noun/v3/allocate.h"
+#include "pkg/noun/version.h"
+
+  /**  Aliases.
+  **/
+#     define     u3v_v3_arvo             u3v_arvo
+#     define     u3H_v3                  u3v_Home
+#     define     u3A_v3                  (&(u3H_v3)->arv_u)
+#     define     u3v_v3_home             u3v_home
+#     define     u3v_v3_rewrite_compact  u3v_rewrite_compact
+
+#endif /* ifndef U3_VORTEX_V3_H */
diff --git a/pkg/noun/version.h b/pkg/noun/version.h
index 125abd684c..5cc6acb86d 100644
--- a/pkg/noun/version.h
+++ b/pkg/noun/version.h
@@ -8,7 +8,8 @@ typedef c3_w       u3v_version;
 
 #define U3V_VER1   1
 #define U3V_VER2   2
-#define U3V_VERLAT U3V_VER2
+#define U3V_VER3   3
+#define U3V_VERLAT U3V_VER3
 
 /* EVENTS
  */
diff --git a/pkg/noun/vortex.h b/pkg/noun/vortex.h
index cbd0f295ff..2d202e831c 100644
--- a/pkg/noun/vortex.h
+++ b/pkg/noun/vortex.h
@@ -37,9 +37,6 @@
 #       define u3H  u3v_Home
 #       define u3A  (&(u3v_Home->arv_u))
 
-  /** Constants.
-  **/
-
   /**  Functions.
   **/
     /* u3v_life(): execute initial lifecycle, producing Arvo core.
diff --git a/pkg/noun/zave.c b/pkg/noun/zave.c
index 0955af906c..596200f887 100644
--- a/pkg/noun/zave.c
+++ b/pkg/noun/zave.c
@@ -5,6 +5,7 @@
 #include "allocate.h"
 #include "hashtable.h"
 #include "imprison.h"
+#include "vortex.h"
 
 /* u3z_key(): construct a memo cache-key.  Arguments retained.
 */
@@ -34,30 +35,60 @@ u3z_key_5(c3_m fun, u3_noun one, u3_noun two, u3_noun tri, u3_noun qua, u3_noun
   return u3nc(fun, u3nq(u3k(one), u3k(two), u3k(tri), u3nc(u3k(qua), u3k(qin))));
 }
 
+/* _har(): get the memo cache for the given cid.
+*/
+static u3p(u3h_root)
+_har(u3a_road* rod_u, u3z_cid cid)
+{
+  switch ( cid ) {
+    case u3z_memo_toss:
+      return rod_u->cax.har_p;
+    case u3z_memo_keep:
+      return rod_u->cax.per_p;
+  }
+  u3_assert(0);
+}
+
 /* u3z_find(): find in memo cache.  Arguments retained.
 */
 u3_weak
-u3z_find(u3_noun key)
+u3z_find(u3z_cid cid, u3_noun key)
 {
-  return u3h_get(u3R->cax.har_p, key);
+  if ( u3z_memo_toss == cid ) {
+    return u3h_get(_har(u3R, cid), key);
+  }
+  else {
+    //  XX needs to be benchmarked (up vs. down search)
+    u3a_road* rod_u = &(u3H->rod_u);
+    while ( 1 ) {
+      u3_weak got = u3h_get(_har(rod_u, cid), key);
+      if ( u3_none != got ) {
+        return got;
+      }
+      if ( 0 == rod_u->kid_p ) {
+        return u3_none;
+      }
+      rod_u = u3to(u3a_road, rod_u->kid_p);
+    };
+  }
 }
 u3_weak
-u3z_find_m(c3_m fun, u3_noun one)
+u3z_find_m(u3z_cid cid, c3_m fun, u3_noun one)
 {
   u3_noun key = u3nc(fun, u3k(one));
   u3_weak val;
-
-  val = u3h_get(u3R->cax.har_p, key);
+  val = u3z_find(cid, key);
   u3z(key);
+
   return val;
 }
 
 /* u3z_save(): save in memo cache. TRANSFER key; RETAIN val
 */
 u3_noun
-u3z_save(u3_noun key, u3_noun val)
+u3z_save(u3z_cid cid, u3_noun key, u3_noun val)
 {
-  u3h_put(u3R->cax.har_p, key, u3k(val));
+  u3h_put(_har(u3R, cid), key, u3k(val));
   u3z(key);
   return val;
 }
@@ -65,28 +96,39 @@ u3z_save(u3_noun key, u3_noun val)
 /* u3z_save_m(): save in memo cache. Arguments retained.
 */
 u3_noun
-u3z_save_m(c3_m fun, u3_noun one, u3_noun val)
+u3z_save_m(u3z_cid cid, c3_m fun, u3_noun one, u3_noun val)
 {
   u3_noun key = u3nc(fun, u3k(one));
 
-  u3h_put(u3R->cax.har_p, key, u3k(val));
+  u3h_put(_har(u3R, cid), key, u3k(val));
   u3z(key);
   return val;
 }
 
-/* u3z_uniq(): uniquify with memo cache.
+/* u3z_uniq(): uniquify with memo cache. XX not used.
 */
 u3_noun
-u3z_uniq(u3_noun som)
+u3z_uniq(u3z_cid cid, u3_noun som)
 {
   u3_noun key = u3nc(c3__uniq, u3k(som));
-  u3_noun val = u3h_get(u3R->cax.har_p, key);
+  u3_noun val = u3h_get(_har(u3R, cid), key);
 
   if ( u3_none != val ) {
     u3z(key); u3z(som); return val;
   }
   else {
-    u3h_put(u3R->cax.har_p, key, u3k(som));
+    u3h_put(_har(u3R, cid), key, u3k(som));
     return som;
   }
 }
+
+/* u3z_reap(): promote memoization cache state.
+*/
+void
+u3z_reap(u3z_cid cid, u3p(u3h_root) har_p)
+{
+  u3_assert(u3z_memo_toss != cid);
+
+  u3h_uni(_har(u3R, cid), har_p);
+  u3h_free(har_p);
+}
diff --git a/pkg/noun/zave.h b/pkg/noun/zave.h
index 44f272da7c..feff83f664 100644
--- a/pkg/noun/zave.h
+++ b/pkg/noun/zave.h
@@ -12,10 +12,18 @@
   ***  and a noun argument to that (logical) function.  Functions
   ***  are predefined by C-level callers, but 0 means nock.
   ***
-  ***  The memo cache is within its road and dies when it falls.
-  ***
   ***  Memo functions RETAIN keys and transfer values.
   **/
+    /* u3z_cid: cache id
+    */
+      typedef enum {
+        u3z_memo_toss  = 0,
+        u3z_memo_keep  = 1,
+        // u3z_memo_ford  = 2,
+        // u3z_memo_ames  = 3,
+        // ...
+      } u3z_cid;
+
     /* u3z_key*(): construct a memo cache-key.  Arguments retained.
     */
       u3_noun u3z_key(c3_m, u3_noun);
@@ -26,20 +34,35 @@
 
     /* u3z_find*(): find in memo cache. Arguments retained
     */
-      u3_weak u3z_find(u3_noun key);
-      u3_weak u3z_find_m(c3_m fun_m, u3_noun one);
+      u3_weak u3z_find(u3z_cid cid, u3_noun key);
+      u3_weak u3z_find_m(u3z_cid cid, c3_m fun_m, u3_noun one);
 
     /* u3z_save(): save in memo cache. TRANSFER key; RETAIN val;
     */
-      u3_noun u3z_save(u3_noun key, u3_noun val);
+      u3_noun u3z_save(u3z_cid cid, u3_noun key, u3_noun val);
 
     /* u3z_save_m(): save in memo cache. Arguments retained
     */
-      u3_noun u3z_save_m(c3_m fun_m, u3_noun one, u3_noun val);
+      u3_noun u3z_save_m(u3z_cid cid, c3_m fun_m, u3_noun one, u3_noun val);
 
     /* u3z_uniq(): uniquify with memo cache.
     */
       u3_noun
-      u3z_uniq(u3_noun som);
+      u3z_uniq(u3z_cid cid, u3_noun som);
+
+    /* u3z_reap(): promote memoization cache state.
+    */
+      void
+      u3z_reap(u3z_cid cid, u3p(u3h_root) har_p);
+
+    /* u3z_free(): free memoization cache.
+    */
+      void
+      u3z_free(u3z_cid cid);
+
+    /* u3z_ream(): refresh after restoring from checkpoint.
+    */
+      void
+      u3z_ream(u3z_cid cid);
 
 #endif /* ifndef U3_ZAVE_H */
diff --git a/pkg/vere/BUILD.bazel b/pkg/vere/BUILD.bazel
index 76f8b47eca..f856ce0047 100644
--- a/pkg/vere/BUILD.bazel
+++ b/pkg/vere/BUILD.bazel
@@ -301,7 +301,7 @@ genrule(
 
     if check && sleep 10 && check; then
       echo "boot success"
-      lensa hood "+hood/exit"
+      lensa hood '+hood/exit'
       while [ -f ./pier/.vere.lock ]; do
         echo "waiting for pier to shut down"
         sleep 5
diff --git a/pkg/vere/db/lmdb.c b/pkg/vere/db/lmdb.c
index 8f8864b77f..f7554019a4 100644
--- a/pkg/vere/db/lmdb.c
+++ b/pkg/vere/db/lmdb.c
@@ -414,7 +414,7 @@ void
 u3_lmdb_read_meta(MDB_env*    env_u,
                   void*       ptr_v,
                   const c3_c* key_c,
-                  void (*read_f)(void*, size_t, void*))
+                  void (*read_f)(void*, ssize_t, void*))
 {
   MDB_txn* txn_u;
   MDB_dbi  mdb_u;
@@ -424,7 +424,7 @@ u3_lmdb_read_meta(MDB_env*    env_u,
   //
   if ( (ret_w = mdb_txn_begin(env_u, 0, MDB_RDONLY, &txn_u)) ) {
     mdb_logerror(stderr, ret_w, "lmdb: meta read: txn_begin fail");
-    return read_f(ptr_v, 0, 0);
+    return read_f(ptr_v, -1, 0);
   }
 
   //  open the database in the transaction
@@ -432,7 +432,7 @@ u3_lmdb_read_meta(MDB_env*    env_u,
   if ( (ret_w =  mdb_dbi_open(txn_u, "META", 0, &mdb_u)) ) {
     mdb_logerror(stderr, ret_w, "lmdb: meta read: dbi_open fail");
     mdb_txn_abort(txn_u);
-    return read_f(ptr_v, 0, 0);
+    return read_f(ptr_v, -1, 0);
   }
 
   //  read by string key, invoking callback with result
@@ -443,7 +443,7 @@ u3_lmdb_read_meta(MDB_env*    env_u,
     if ( (ret_w = mdb_get(txn_u, mdb_u, &key_u, &val_u)) ) {
       mdb_logerror(stderr, ret_w, "lmdb: read failed");
       mdb_txn_abort(txn_u);
-      return read_f(ptr_v, 0, 0);
+      return read_f(ptr_v, -1, 0);
     }
     else {
       read_f(ptr_v, val_u.mv_size, val_u.mv_data);
diff --git a/pkg/vere/db/lmdb.h b/pkg/vere/db/lmdb.h
index aab4e6c9f7..43c6b433ff 100644
--- a/pkg/vere/db/lmdb.h
+++ b/pkg/vere/db/lmdb.h
@@ -63,7 +63,7 @@
       u3_lmdb_read_meta(MDB_env*    env_u,
                         void*       ptr_v,
                         const c3_c* key_c,
-                        void     (*read_f)(void*, size_t, void*));
+                        void     (*read_f)(void*, ssize_t, void*));
 
     /* u3_lmdb_save_meta(): save by string into the META db.
     */
diff --git a/pkg/vere/disk.c b/pkg/vere/disk.c
index 45a2c21cef..de141988bd 100644
--- a/pkg/vere/disk.c
+++ b/pkg/vere/disk.c
@@ -662,26 +662,26 @@ u3_disk_save_meta(MDB_env* mdb_u,
   return c3y;
 }
 
+typedef struct {
+  ssize_t hav_i;
+  c3_y    buf_y[16];
+} _mdb_val;
+
+
 /* _disk_meta_read_cb(): copy [val_p] to atom [ptr_v] if present.
 */
 static void
-_disk_meta_read_cb(void* ptr_v, size_t val_i, void* val_p)
+_disk_meta_read_cb(void* ptr_v, ssize_t val_i, void* val_v)
 {
-  u3_weak* mat = ptr_v;
+  _mdb_val* val_u = ptr_v;
+  c3_y*     dat_y = (c3_y*)val_v;
 
-  if ( val_p ) {
-    *mat = u3i_bytes(val_i, val_p);
-  }
-}
+  memset(val_u->buf_y, 0, sizeof(val_u->buf_y));
+  val_u->hav_i = val_i;
 
-/* _disk_read_meta(): read metadata at [key_c], deserialize.
-*/
-static u3_weak
-_disk_read_meta(MDB_env* mdb_u, const c3_c* key_c)
-{
-  u3_weak dat = u3_none;
-  u3_lmdb_read_meta(mdb_u, &dat, key_c, _disk_meta_read_cb);
-  return dat;
+  if ( 0 < val_i ) {
+    memcpy(val_u->buf_y, dat_y, c3_min(val_i, sizeof(val_u->buf_y)));
+  }
 }
 
 /* u3_disk_read_meta(): read metadata.
@@ -692,60 +692,104 @@ u3_disk_read_meta(MDB_env* mdb_u,
                   c3_o*    fak_o,
                   c3_w*    lif_w)
 {
-  u3_weak ver, who, fak, lif;
+  _mdb_val val_u;
 
-  if ( u3_none == (ver = _disk_read_meta(mdb_u, "version")) ) {
+  //  version
+  //
+  u3_lmdb_read_meta(mdb_u, &val_u, "version", _disk_meta_read_cb);
+
+  if ( 0 > val_u.hav_i ) {
     fprintf(stderr, "disk: read meta: no version\r\n");
     return c3n;
   }
-  if ( u3_none == (who = _disk_read_meta(mdb_u, "who")) ) {
-    fprintf(stderr, "disk: read meta: no indentity\r\n");
+  else if ( (1 != val_u.hav_i) || (1 != *val_u.buf_y) ) {
+    fprintf(stderr, "disk: read meta: unknown version %u\r\n", *val_u.buf_y);
     return c3n;
   }
-  if ( u3_none == (fak = _disk_read_meta(mdb_u, "fake")) ) {
-    fprintf(stderr, "disk: read meta: no fake bit\r\n");
+
+  //  identity
+  //
+  u3_lmdb_read_meta(mdb_u, &val_u, "who", _disk_meta_read_cb);
+
+  if ( 0 > val_u.hav_i ) {
+    fprintf(stderr, "disk: read meta: no identity\r\n");
     return c3n;
   }
-  if ( u3_none == (lif = _disk_read_meta(mdb_u, "life")) ) {
-    fprintf(stderr, "disk: read meta: no lifecycle length\r\n");
-    return c3n;
+  else if ( 16 < val_u.hav_i ) {
+    //  NB: non-fatal
+    //
+    fprintf(stderr, "disk: read meta: strange identity\r\n");
   }
 
-  {
-    c3_o val_o = c3y;
+  if ( who_d ) {
+    c3_y* byt_y = val_u.buf_y;
+
+    who_d[0] = (c3_d)byt_y[0]
+             | (c3_d)byt_y[1] << 8
+             | (c3_d)byt_y[2] << 16
+             | (c3_d)byt_y[3] << 24
+             | (c3_d)byt_y[4] << 32
+             | (c3_d)byt_y[5] << 40
+             | (c3_d)byt_y[6] << 48
+             | (c3_d)byt_y[7] << 56;
+
+    byt_y += 8;
+    who_d[1] = (c3_d)byt_y[0]
+             | (c3_d)byt_y[1] << 8
+             | (c3_d)byt_y[2] << 16
+             | (c3_d)byt_y[3] << 24
+             | (c3_d)byt_y[4] << 32
+             | (c3_d)byt_y[5] << 40
+             | (c3_d)byt_y[6] << 48
+             | (c3_d)byt_y[7] << 56;
+  }
+
+  //  fake bit
+  //
+  u3_lmdb_read_meta(mdb_u, &val_u, "fake", _disk_meta_read_cb);
 
-    if ( 1 != ver ) {
-      fprintf(stderr, "disk: read meta: unknown version %u\r\n", ver);
-      val_o = c3n;
-    }
-    else if ( !((c3y == fak ) || (c3n == fak )) ) {
-      fprintf(stderr, "disk: read meta: invalid fake bit\r\n");
-      val_o = c3n;
-    }
-    else if ( c3n == u3a_is_cat(lif) ) {
-      fprintf(stderr, "disk: read meta: invalid lifecycle length\r\n");
-      val_o = c3n;
+  if ( 0 > val_u.hav_i ) {
+    fprintf(stderr, "disk: read meta: no fake bit\r\n");
+    return c3n;
+  }
+  else if ( 0 == val_u.hav_i ) {
+    if ( fak_o ) {
+      *fak_o = 0;
     }
-
-    if ( c3n == val_o ) {
-      u3z(ver); u3z(who); u3z(fak); u3z(lif);
-      return c3n;
+  }
+  else if ( (1 == val_u.hav_i) || !((*val_u.buf_y) >> 1) ) {
+    if ( fak_o ) {
+      *fak_o = (*val_u.buf_y) & 1;
     }
   }
-
-  if ( who_d ) {
-    u3r_chubs(0, 2, who_d, who);
+  else {
+    fprintf(stderr, "disk: read meta: invalid fake bit %u %zd\r\n",
+                    *val_u.buf_y, val_u.hav_i);
+    return c3n;
   }
 
-  if ( fak_o ) {
-    *fak_o = fak;
+  //  life
+  //
+  u3_lmdb_read_meta(mdb_u, &val_u, "life", _disk_meta_read_cb);
+
+  if ( 0 > val_u.hav_i ) {
+    fprintf(stderr, "disk: read meta: no lifecycle length\r\n");
+    return c3n;
+  }
+  else if ( 4 < val_u.hav_i ) {
+    //  NB: non-fatal
+    //
+    fprintf(stderr, "disk: read meta: strange life\r\n");
   }
 
   if ( lif_w ) {
-    *lif_w = lif;
+    c3_y* byt_y = val_u.buf_y;
+    *lif_w = (c3_w)byt_y[0]
+           | (c3_w)byt_y[1] << 8
+           | (c3_w)byt_y[2] << 16
+           | (c3_w)byt_y[3] << 24;
   }
 
-  u3z(who);
   return c3y;
 }
 
diff --git a/pkg/vere/lord.c b/pkg/vere/lord.c
index cf1dfcfba9..a63824ae9b 100644
--- a/pkg/vere/lord.c
+++ b/pkg/vere/lord.c
@@ -1160,10 +1160,11 @@ u3_lord_init(c3_c* pax_c, c3_w wag_w, c3_d key_d[4], u3_lord_cb cb_u)
   //  spawn new process and connect to it
   //
   {
-    c3_c* arg_c[11];
+    c3_c* arg_c[12];
     c3_c  key_c[256];
     c3_c  wag_c[11];
     c3_c  hap_c[11];
+    c3_c  per_c[11];
     c3_c  cev_c[11];
     c3_c  lom_c[11];
     c3_c  tos_c[11];
@@ -1179,6 +1180,8 @@ u3_lord_init(c3_c* pax_c, c3_w wag_w, c3_d key_d[4], u3_lord_cb cb_u)
 
     sprintf(hap_c, "%u", u3_Host.ops_u.hap_w);
 
+    sprintf(per_c, "%u", u3_Host.ops_u.per_w);
+
     sprintf(lom_c, "%u", u3_Host.ops_u.lom_y);
 
     sprintf(tos_c, "%u", u3C.tos_w);
@@ -1208,7 +1211,8 @@ u3_lord_init(c3_c* pax_c, c3_w wag_w, c3_d key_d[4], u3_lord_cb cb_u)
     }
 
     arg_c[9] = tos_c;
-    arg_c[10] = NULL;
+    arg_c[10] = per_c;
+    arg_c[11] = NULL;
 
     uv_pipe_init(u3L, &god_u->inn_u.pyp_u, 0);
     uv_timer_init(u3L, &god_u->out_u.tim_u);
diff --git a/pkg/vere/main.c b/pkg/vere/main.c
index 9a1680347c..930d8981ad 100644
--- a/pkg/vere/main.c
+++ b/pkg/vere/main.c
@@ -183,6 +183,9 @@ _main_init(void)
   u3_Host.ops_u.veb = c3n;
   u3_Host.ops_u.puf_c = "jam";
   u3_Host.ops_u.hap_w = 50000;
+  u3C.hap_w = u3_Host.ops_u.hap_w;
+  u3_Host.ops_u.per_w = 50000;
+  u3C.per_w = u3_Host.ops_u.per_w;
   u3_Host.ops_u.kno_w = DefaultKernel;
 
   u3_Host.ops_u.sap_w = 120;    /* aka 2 minutes */
@@ -247,6 +250,7 @@ _main_getopt(c3_i argc, c3_c** argv)
     { "loom",                required_argument, NULL, c3__loom },
     { "local",               no_argument,       NULL, 'L' },
     { "lite-boot",           no_argument,       NULL, 'l' },
+    { "keep-cache-limit",    required_argument, NULL, 'M' },
     { "replay-to",           required_argument, NULL, 'n' },
     { "profile",             no_argument,       NULL, 'P' },
     { "ames-port",           required_argument, NULL, 'p' },
@@ -279,7 +283,7 @@ _main_getopt(c3_i argc, c3_c** argv)
   };
 
   while ( -1 != (ch_i=getopt_long(argc, argv,
-                 "A:B:C:DF:G:H:I:J:K:LPRSX:Y:Z:ab:c:de:gi:jk:ln:p:qr:stu:vw:x",
+                 "A:B:C:DF:G:H:I:J:K:LM:PRSX:Y:Z:ab:c:de:gi:jk:ln:p:qr:stu:vw:x",
                  lop_u, &lid_i)) )
   {
     switch ( ch_i ) {
@@ -365,6 +369,7 @@ _main_getopt(c3_i argc, c3_c** argv)
         if ( c3n == _main_readw(optarg, 1000000000, &u3_Host.ops_u.hap_w) ) {
           return c3n;
         }
+        u3C.hap_w = u3_Host.ops_u.hap_w;
         break;
       }
       case 'c': {
@@ -412,6 +417,13 @@ _main_getopt(c3_i argc, c3_c** argv)
         u3_Host.ops_u.key_c = _main_repath(optarg);
         break;
       }
+      case 'M': {
+        if ( c3n == _main_readw(optarg, 1000000000, &u3_Host.ops_u.per_w) ) {
+          return c3n;
+        }
+        u3C.per_w = u3_Host.ops_u.per_w;
+        break;
+      }
       case 'n': {
         u3_Host.ops_u.til_c = strdup(optarg);
         break;
@@ -765,6 +777,7 @@ u3_ve_usage(c3_i argc, c3_c** argv)
     "-L, --local                   Local networking only\n",
     "    --loom                    Set loom to binary exponent (31 == 2GB)\n"
     "-l, --lite-boot               Most-minimal startup\n",
+    "-M, --keep-cache-limit LIMIT  Set persistent memo cache max size; 0 means default\n",
     "-n, --replay-to NUMBER        Replay up to event\n",
     "-P, --profile                 Profiling\n",
     "-p, --ames-port PORT          Set the ames port to bind to\n",
@@ -1076,6 +1089,8 @@ _cw_serf_commence(c3_i argc, c3_c* argv[])
     exit(1);
   }
 
+  //  XX use named arguments and getopt
+
   c3_d       eve_d = 0;
   uv_loop_t* lup_u = u3_Host.lup_u = uv_default_loop();
   c3_c*      dir_c = argv[2];
@@ -1087,6 +1102,7 @@ _cw_serf_commence(c3_i argc, c3_c* argv[])
   c3_c*      eve_c = argv[7];
   c3_c*      eph_c = argv[8];
   c3_c*      tos_c = argv[9];
+  c3_c*      per_c = argv[10];
   c3_w       tos_w;
 
   _cw_init_io(lup_u);
@@ -1111,7 +1127,8 @@ _cw_serf_commence(c3_i argc, c3_c* argv[])
     //  XX check return
     //
     sscanf(wag_c, "%" SCNu32, &u3C.wag_w);
-    sscanf(hap_c, "%" SCNu32, &u3_Host.ops_u.hap_w);
+    sscanf(hap_c, "%" SCNu32, &u3C.hap_w);
+    sscanf(per_c, "%" SCNu32, &u3C.per_w);
     sscanf(lom_c, "%" SCNu32, &lom_w);
 
     if ( 1 != sscanf(tos_c, "%" SCNu32, &u3C.tos_w) ) {
diff --git a/pkg/vere/serf.c b/pkg/vere/serf.c
index cfbbc47be3..cec8bece55 100644
--- a/pkg/vere/serf.c
+++ b/pkg/vere/serf.c
@@ -51,6 +51,25 @@ ::    next steps:
 --
 */
 
+/*  serf memory-threshold levels
+*/
+enum {
+  _serf_mas_init = 0,  //  initial
+  _serf_mas_hit1 = 1,  //  past low threshold
+  _serf_mas_hit0 = 2   //  have high threshold
+};
+
+/*  serf post-op flags
+*/
+enum {
+  _serf_fag_none = 0,       //  nothing to do
+  _serf_fag_hit1 = 1 << 0,  //  hit low threshold
+  _serf_fag_hit0 = 1 << 1,  //  hit high threshold
+  _serf_fag_mute = 1 << 2,  //  mutated state
+  _serf_fag_much = 1 << 3,  //  bytecode hack
+  _serf_fag_vega = 1 << 4   //  kernel reset
+};
+
 /* _serf_grab(): garbage collect, checking for profiling. RETAIN.
 */
 static void
@@ -174,28 +193,53 @@ u3_serf_grab(void)
 void
 u3_serf_post(u3_serf* sef_u)
 {
-  if ( c3y == sef_u->rec_o ) {
+  if ( sef_u->fag_w & _serf_fag_hit1 ) {
+    if ( u3C.wag_w & u3o_verbose ) {
+      u3l_log("serf: threshold 1: %u", u3h_wyt(u3R->cax.per_p));
+    }
+    u3h_trim_to(u3R->cax.per_p, u3h_wyt(u3R->cax.per_p) / 2);
+    u3m_reclaim();
+  }
+
+  if ( sef_u->fag_w & _serf_fag_much ) {
+    u3m_reclaim();
+  }
+
+  if ( sef_u->fag_w & _serf_fag_vega ) {
+    u3h_trim_to(u3R->cax.per_p, u3h_wyt(u3R->cax.per_p) / 2);
     u3m_reclaim();
-    sef_u->rec_o = c3n;
   }
 
   //  XX this runs on replay too, |mass s/b elsewhere
   //
-  if ( c3y == sef_u->mut_o ) {
+  if ( sef_u->fag_w & _serf_fag_mute ) {
     _serf_grab(sef_u->sac);
     sef_u->sac   = u3_nul;
-    sef_u->mut_o = c3n;
   }
 
-  if ( c3y == sef_u->pac_o ) {
+  if ( sef_u->fag_w & _serf_fag_hit0 ) {
+    if ( u3C.wag_w & u3o_verbose ) {
+      u3l_log("serf: threshold 0: per_p %u", u3h_wyt(u3R->cax.per_p));
+    }
+    u3h_free(u3R->cax.per_p);
+    u3R->cax.per_p = u3h_new_cache(u3C.per_w);
     u3a_print_memory(stderr, "serf: pack: gained", u3m_pack());
     u3l_log("");
-    sef_u->pac_o = c3n;
   }
 
   if ( u3C.wag_w & u3o_toss ) {
     u3m_toss();
   }
+
+  sef_u->fag_w = _serf_fag_none;
+}
+
+/* _serf_curb(): check for memory threshold
+*/
+static inline c3_t
+_serf_curb(c3_w pre_w, c3_w pos_w, c3_w hes_w)
+{
+  return (pre_w > hes_w) && (pos_w <= hes_w);
 }
 
 /* _serf_sure_feck(): event succeeded, send effects.
@@ -203,9 +247,6 @@ u3_serf_post(u3_serf* sef_u)
 static u3_noun
 _serf_sure_feck(u3_serf* sef_u, c3_w pre_w, u3_noun vir)
 {
-  c3_o rec_o = c3n;
-  c3_o pac_o = c3n;
-
   //  intercept |mass, observe |reset
   //
   {
@@ -236,7 +277,7 @@ _serf_sure_feck(u3_serf* sef_u, c3_w pre_w, u3_noun vir)
       //  reclaim memory from persistent caches on |reset
       //
       if ( c3__vega == u3h(fec) ) {
-        rec_o = c3y;
+        sef_u->fag_w |= _serf_fag_vega;
       }
 
       riv = u3t(riv);
@@ -253,39 +294,60 @@ _serf_sure_feck(u3_serf* sef_u, c3_w pre_w, u3_noun vir)
   //    For future flexibility, the urgency of the notification is represented
   //    by a *decreasing* number: 0 is maximally urgent, 1 less so, &c.
   //
-  //    high-priority: 2^22 contiguous words remaining (~8 MB)
+  //    high-priority: 2^25 contiguous words remaining (~128 MB)
   //    low-priority:  2^27 contiguous words remaining (~536 MB)
-  //    XX maybe use 2^23 (~16 MB) and 2^26 (~268 MB?
+  //
+  //    once a threshold is hit, it's not a candidate to be hit again
+  //    until memory usage falls below:
+  //
+  //    high-priority: 2^26 contiguous words remaining (~256 MB)
+  //    low-priority:  2^26 + 2^27 contiguous words remaining (~768 MB)
   //
   //    XX these thresholds should trigger notifications sent to the king
   //    instead of directly triggering these remedial actions.
   //
   {
     u3_noun pri = u3_none;
-    c3_w pos_w = u3a_open(u3R);
-    c3_w low_w = (1 << 27);
-    c3_w hig_w = (1 << 22);
+    c3_w  pos_w = u3a_open(u3R);
 
-    if ( (pre_w > low_w) && !(pos_w > low_w) ) {
-      //  XX set flag(s) in u3V so we don't repeat endlessly?
-      //
-      pac_o = c3y;
-      rec_o = c3y;
-      pri   = 1;
+    //  if contiguous free space shrunk, check thresholds
+    //  (and track state to avoid thrashing)
+    //
+    if ( pos_w < pre_w ) {
+      if (  (_serf_mas_hit0 != sef_u->mas_w)
+         && _serf_curb(pre_w, pos_w, 1 << 25) )
+      {
+        sef_u->mas_w  = _serf_mas_hit0;
+        sef_u->fag_w |= _serf_fag_hit0;
+        pri           = 0;
+      }
+      else if (  (_serf_mas_init == sef_u->mas_w)
+              && _serf_curb(pre_w, pos_w, 1 << 27) )
+      {
+        sef_u->mas_w  = _serf_mas_hit1;
+        sef_u->fag_w |= _serf_fag_hit1;
+        pri         = 1;
+      }
     }
-    else if ( (pre_w > hig_w) && !(pos_w > hig_w) ) {
-      pac_o = c3y;
-      rec_o = c3y;
-      pri   = 0;
+    else if ( _serf_mas_init != sef_u->mas_w ) {
+      if ( ((1 << 26) + (1 << 27)) < pos_w ) {
+        sef_u->mas_w = _serf_mas_init;
+      }
+      else if (  (_serf_mas_hit0 == sef_u->mas_w)
+              && ((1 << 26) < pos_w) )
+      {
+        sef_u->mas_w = _serf_mas_hit1;
+      }
     }
+
     //  reclaim memory from persistent caches periodically
     //
     //    XX this is a hack to work two things
     //    - bytecode caches grow rapidly and can't be simply capped
     //    - we don't make very effective use of our free lists
     //
-    else if ( 0 == (sef_u->dun_d % 1000ULL) ) {
-      rec_o = c3y;
+    if ( !(sef_u->dun_d % 1024ULL) ) {
+      sef_u->fag_w |= _serf_fag_much;
     }
 
     //  notify daemon of memory pressure via "fake" effect
@@ -297,9 +359,6 @@ _serf_sure_feck(u3_serf* sef_u, c3_w pre_w, u3_noun vir)
     }
   }
 
-  sef_u->rec_o = c3o(sef_u->rec_o, rec_o);
-  sef_u->pac_o = c3o(sef_u->pac_o, pac_o);
-
   return vir;
 }
 
@@ -314,7 +373,7 @@ _serf_sure_core(u3_serf* sef_u, u3_noun cor)
   u3A->roc     = cor;
   u3A->eve_d   = sef_u->dun_d;
   sef_u->mug_l = u3r_mug(u3A->roc);
-  sef_u->mut_o = c3y;
+  sef_u->fag_w |= _serf_fag_mute;
 }
 
 /* _serf_sure(): event succeeded, save state and process effects.
@@ -1016,9 +1075,7 @@ u3_serf_init(u3_serf* sef_u)
   //   }
   // }
 
-  sef_u->pac_o = c3n;
-  sef_u->rec_o = c3n;
-  sef_u->mut_o = c3n;
+  sef_u->fag_w = _serf_fag_none;
   sef_u->sac   = u3_nul;
 
   return rip;
diff --git a/pkg/vere/serf.h b/pkg/vere/serf.h
index 5808f362e7..7cd2ca47d0 100644
--- a/pkg/vere/serf.h
+++ b/pkg/vere/serf.h
@@ -11,9 +11,8 @@
         c3_d    sen_d;             //  last event requested
         c3_d    dun_d;             //  last event processed
         c3_l    mug_l;             //  hash of state
-        c3_o    pac_o;             //  pack kernel
-        c3_o    rec_o;             //  reclaim cache
-        c3_o    mut_o;             //  mutated kerne
+        c3_w    mas_w;             //  memory threshold state
+        c3_w    fag_w;             //  post-op flags
         u3_noun sac;               //  space measurementl
         void  (*xit_f)(void);      //  exit callback
       } u3_serf;
diff --git a/pkg/vere/vere.h b/pkg/vere/vere.h
index b2b78b5e81..9527246e19 100644
--- a/pkg/vere/vere.h
+++ b/pkg/vere/vere.h
@@ -265,7 +265,7 @@
         c3_o    abo;                        //  -a, abort aggressively
         c3_c*   pil_c;                      //  -B, bootstrap from
         c3_c*   bin_c;                      //  -b, http server bind ip
-        c3_w    hap_w;                      //  -C, cap memo cache
+        c3_w    hap_w;                      //  -C, cap transient memo cache
         c3_o    dry;                        //  -D, dry compute, no checkpoint
         c3_o    dem;                        //  -d, daemon
         c3_c*   eth_c;                      //  -e, ethereum node url
@@ -283,6 +283,7 @@
         c3_o    lit;                        //  -l, lite mode
         c3_y    lom_y;                      //      loom bex
         c3_y    lut_y;                      //      urth-loom bex
+        c3_w    per_w;                      //  -M, cap persistent memo cache
         c3_c*   til_c;                      //  -n, play till eve_d
         c3_o    pro;                        //  -P, profile
         c3_s    per_s;                      //      http port