Based on the documentation from Marcus Comstedt's Dreamcast Programming page.
Currently can only read the memory card's blocks and print some of the data.
Still a lot of work left to do.
$ ./mmem img/mem3.BIN
[255] = Root Block
custom color: Y
color: rgba(31, 31, 255, 24)
created: 2004-01-29 17:07
FAT block: 254
directory blocks: 253-241
icon shape: 34
user blocks: 200
[254] = FAT Block
[000]=0001 [001]=0002 [002]=0003 [003]=0004 [004]=0005 [005]=0006 [006]=LAST [007]=____
[008]=____ [009]=____ [010]=____ [011]=____ [012]=LAST [013]=0012 [014]=0013 [015]=0014
[016]=0015 [017]=0016 [018]=0017 [019]=0018 [020]=0019 [021]=LAST [022]=0021 [023]=0022
[024]=0023 [025]=0024 [026]=0025 [027]=0026 [028]=0027 [029]=0028 [030]=0029 [031]=LAST
[032]=0031 [033]=0032 [034]=LAST [035]=0034 [036]=0035 [037]=LAST [038]=0037 [039]=0038
[040]=LAST [041]=0040 [042]=LAST [043]=0042 [044]=0043 [045]=LAST [046]=0045 [047]=0046
[048]=0047 [049]=0048 [050]=0030 [051]=LAST [052]=0051 [053]=0052 [054]=0053 [055]=LAST
[056]=0055 [057]=0056 [058]=0057 [059]=0058 [060]=0059 [061]=0060 [062]=0061 [063]=0062
[064]=0063 [065]=LAST [066]=0065 [067]=LAST [068]=0067 [069]=0068 [070]=LAST [071]=0070
[072]=0050 [073]=0072 [074]=0073 [075]=0074 [076]=0075 [077]=0076 [078]=0077 [079]=0078
[080]=LAST [081]=0080 [082]=0081 [083]=LAST [084]=0083 [085]=0084 [086]=0085 [087]=0086
[088]=0087 [089]=LAST [090]=0089 [091]=0090 [092]=0091 [093]=0092 [094]=0093 [095]=0094
[096]=0095 [097]=0096 [098]=0097 [099]=0098 [100]=0099 [101]=0100 [102]=0101 [103]=0102
[104]=0103 [105]=0104 [106]=0105 [107]=LAST [108]=0107 [109]=0108 [110]=0109 [111]=0110
[112]=0111 [113]=0112 [114]=0113 [115]=0114 [116]=0115 [117]=0116 [118]=0117 [119]=0118
[120]=0119 [121]=0120 [122]=0121 [123]=0122 [124]=0123 [125]=LAST [126]=0125 [127]=0126
[128]=0127 [129]=0128 [130]=0129 [131]=0130 [132]=0131 [133]=0132 [134]=0133 [135]=0134
[136]=0135 [137]=0136 [138]=0137 [139]=0138 [140]=0139 [141]=LAST [142]=0141 [143]=0142
[144]=0143 [145]=LAST [146]=0145 [147]=0146 [148]=0147 [149]=0148 [150]=0149 [151]=0150
[152]=0151 [153]=0152 [154]=0153 [155]=0154 [156]=0155 [157]=0156 [158]=0157 [159]=0158
[160]=0079 [161]=0160 [162]=0161 [163]=0162 [164]=0163 [165]=0164 [166]=0165 [167]=0166
[168]=LAST [169]=0168 [170]=LAST [171]=0170 [172]=0171 [173]=0172 [174]=0173 [175]=0174
[176]=0175 [177]=0176 [178]=0177 [179]=0178 [180]=0179 [181]=0180 [182]=0181 [183]=0182
[184]=0183 [185]=0184 [186]=0185 [187]=0186 [188]=0187 [189]=0188 [190]=LAST [191]=0190
[192]=LAST [193]=0192 [194]=0193 [195]=0194 [196]=0195 [197]=0196 [198]=0197 [199]=0198
[200]=____ [201]=____ [202]=____ [203]=____ [204]=____ [205]=____ [206]=____ [207]=____
[208]=____ [209]=____ [210]=____ [211]=____ [212]=____ [213]=____ [214]=____ [215]=____
[216]=____ [217]=____ [218]=____ [219]=____ [220]=____ [221]=____ [222]=____ [223]=____
[224]=____ [225]=____ [226]=____ [227]=____ [228]=____ [229]=____ [230]=____ [231]=____
[232]=____ [233]=____ [234]=____ [235]=____ [236]=____ [237]=____ [238]=____ [239]=____
[240]=____ [241]=LAST [242]=0241 [243]=0242 [244]=0243 [245]=0244 [246]=0245 [247]=0246
[248]=0247 [249]=0248 [250]=0249 [251]=0250 [252]=0251 [253]=0252 [254]=LAST [255]=0250
[253] = FAT Directory Block
[253]
#000 FILE:
title: HYDRO THUNDER
app: HYDRO THUNDER
desc: SAVE GAME
name: HYDRO___SYS
crc: 0x2cb5
icon(s): 1
animation speed: 1
size: 207 bytes
first block: #199
created: 2704-02-29 11:05
offset: 000
#001 FILE:
title: OOGA BOOGA GAME DATA
app: OOGA BOOGA
desc: OOGA BOOGA DATA
name: OOGA___BOOGA
crc: 0x926a
icon(s): 1
animation speed: 59
size: 193 bytes
first block: #191
created: 2604-02-29 11:05
offset: 000
#002 FILE:
title: PSOV2/MAIN_DATA
app:
desc: PSOV2/MAIN_DATA
name: PSO______SYS
crc: 0xdeb8
icon(s): 1
animation speed: 1
size: 174 bytes
first block: #159
created: 2404-02-29 11:05
offset: 000
#003 FILE:
title: READY 2 RUMBLE BOXING: ROUND 2
app: READY 2 RUMBLE 2
desc: SAVE GAME
name: RUMBLER2.SYS
crc: 0x4c95
icon(s): 2
animation speed: 25
size: 148 bytes
first block: #144
created: 2304-02-29 11:05
offset: 000
#004 FILE:
title: SOLDIER OF FORTUNE
app: SOLDIEROFFORTUNE
desc: TRAIN
name: SFORTUNE.000
crc: 0xe65e
icon(s): 1
animation speed: 0
size: 156 bytes
first block: #140
created: 2204-02-29 11:05
offset: 000
#005 FILE:
title: SNOCROSS CHAMPIONSHIP RACING
app: SNOCROSS
desc: GAME SETTINGS
name: SNOCROSS_CFG
crc: 0x0000
icon(s): 1
animation speed: 10
size: 142 bytes
first block: #124
created: 2104-02-29 11:05
offset: 000
#006 FILE:
title: SONIC ADVENTURE 2 / Main File
app:
desc: MAIN FILE
name: SONIC2___S01
crc: 0x017d
icon(s): 1
animation speed: 0
size: 124 bytes
first block: #106
created: 2004-02-29 11:05
offset: 000
#007 FILE:
title: TD-VRally Preferences
app:
desc: TDVR CONFIG
name: TDVRALLY_GAM
crc: 0x6377
icon(s): 1
animation speed: 1
size: 94 bytes
first block: #88
created: 2504-02-29 11:05
offset: 000
#008 FILE:
title: TEST (ITALY)
app:
desc: VR2 TRACK
name: TDVRALLY_T00
crc: 0xe470
icon(s): 1
animation speed: 1
size: 85 bytes
first block: #82
created: 2404-02-29 11:05
offset: 000
#009 FILE:
title: BANGAI-O
app:
desc: AUTO SAVE DATA
name: BANGAIO_DAT
crc: 0xda7a
icon(s): 3
animation speed: 6
size: 54 bytes
first block: #49
created: 2204-02-29 11:05
offset: 000
#010 FILE:
title: CONFIDENTIAL MISSION
app:
desc: CM_MAIN_DATA
name: C_MISSION_DC
crc: 0x0bf0
icon(s): 1
animation speed: 0
size: 47 bytes
first block: #44
created: 2104-02-29 11:06
offset: 000
#011 FILE:
title: (c)Interact - www.gameshark.com
app:
desc: GameShark Code
name: CDX_CODES_00
crc: 0x0000
icon(s): 1
animation speed: 0
size: 43 bytes
first block: #41
created: 2004-02-29 11:06
offset: 000
#012 FILE:
title: (c)Interact - www.gameshark.com
app:
desc: GameShark Code
name: CDX_SETTINGS
crc: 0x0000
icon(s): 1
animation speed: 0
size: 42 bytes
first block: #39
created: 1904-02-29 11:06
offset: 000
#013 FILE:
title: CHUCHU!/PZ EDIT
app:
desc: CHU_CHU__E01
name: CHU_CHU__E01
crc: 0x2099
icon(s): 1
animation speed: 1
size: 39 bytes
first block: #36
created: 1804-02-29 11:06
offset: 000
#014 FILE:
title: CHUCHU!/PZ EDIT
app:
desc: CHU_CHU__E02
name: CHU_CHU__E02
crc: 0x6b32
icon(s): 1
animation speed: 1
size: 36 bytes
first block: #33
created: 1704-02-29 11:06
offset: 000
#015 FILE:
title: CHUCHU!/MAIN
app:
desc: CHU_CHU__RCT
name: CHU_CHU__RCT
crc: 0x9ef3
icon(s): 1
animation speed: 1
size: 72 bytes
first block: #69
created: 1998-11-27 00:01
offset: 000
[252]
#016 FILE:
title: HIDDEN FILE
desc: VMU Tool icon
name: ICONDATA_VMS
crc: 0x63bb
icon(s): 57277
animation speed: 32635
size: 73 bytes
first block: #71
created: 1998-11-27 02:50
offset: 000
#017 FILE:
title: PROJECT JUSTICE
app:
desc: SYSTEM FILE
name: PJUSTICE_SYS
crc: 0x49ee
icon(s): 1
animation speed: 1
size: 68 bytes
first block: #66
created: 1998-11-27 00:01
offset: 000
#018 FILE:
title: SONIC ADVENTURE / Main Save File
app: 0000000000000000
desc: MAIN_SAVE_FILE
name: SONICADV_INT
crc: 0x0d4a
icon(s): 2
animation speed: 20
size: 74 bytes
first block: #64
created: 1998-11-27 00:10
offset: 000
#019 FILE:
title: ????
app:
desc: ????
name: PUYOFEVERSYS
crc: 0xfd47
icon(s): 1
animation speed: 1
size: 58 bytes
first block: #54
created: 1998-11-27 00:00
offset: 000
#020 FILE:
title: Draconus: Cult of the Wyrm
app: DRACONUS
desc: treetop
name: DRACONUS.001
crc: 0x6fff
icon(s): 1
animation speed: 1
size: 209 bytes
first block: #189
created: 1504-02-29 11:06
offset: 000
#021 FILE:
title: EXPENDABLE
app: ;S!7L
desc: LEVEL 03
name: EXPENDAB.001
crc: 0x6a3a
icon(s): 1
animation speed: 1
size: 171 bytes
first block: #169
created: 1404-02-29 11:06
offset: 000
#022 GAME:
title: VMU Script
app:
desc: Logic
name: LOGIC
crc: 0x0000
icon(s): 1
animation speed: 10
size: 7 bytes
first block: #0
created: 2004-02-12 23:14
offset: 001
#023 FILE:
title: Arcadia Soltis
app:
desc: Arcadia Savefile
name: ARCADIA_E001
crc: 0x47c7
icon(s): 1
animation speed: 8
size: 194 bytes
first block: #167
created: 2006-06-04 11:14
offset: 000
#024 FILE:
title: GRANDIA2 NEW VALMAR, ROOM OF CHA
app:
desc: GRANDIA2
name: GRANDIA2_003
crc: 0xe457
icon(s): 1
animation speed: 1
size: 29 bytes
first block: #20
created: 2003-10-24 01:23
offset: 000
[251]
[250]
[249]
[248]
[247]
[246]
[245]
[244]
[243]
[242]
[241]