Errors with Krikzz's Mega-CD Verificator

[ekeeke]

When being run in Genesis Plus GX, Krikzz's Mega-CD Verificator Test ROM reports several errors:

This test ROM has been reported (by Krikzz) to run without errors on CDX/Multimega hardware.

[ekeeke]

Following tests have been fixed by 58accf0:
COLOR CALC : TEST 0x05
REG X002: TEST 0x29
REG 8030: TEST 0x02

[ekeeke]

REG 2006 TEST 0x02 fixed by ee5b917 and 7fe8d95

[DevsArchive]

Just a heads up: I had a friend run the verificator on his European Model 1 MCD, and it reported this:

I do know that only NTSC seems to have been tested on krikzz's end, so the timing stuff probably is no surprise, but the CDC register thing is kind of interesting. Notably, it doesn't report back the same behavior with the supposed "RS" flag that the verificator's source code mentions. Originally, I had a PR that addressed this along with a couple other things, but this kinda complicates this a bit, in my opinion.

[ekeeke]

Yes, this test was confirmed as not working on most Sega CD / Mega CD models by Blastem author (see http://gendev.spritesmind.net/forum/viewtopic.php?f=5&t=3166&start=25) so I suspect it only works on the specific CDC model (LC8913) used in CDX/Multimega and X-Eye/Wondermega M2. If you look at the (very limited) LC8913 datasheet, it seems there are some additional configuration (double/quad speed playback, configurable CD input stream format,...) that are not mentionned in the other chips of same family (LC89510 and LC89515) used in Model 1 / Model 2 hardware so it is quite possible this particular chip model extends the number of available registers and use 5 bits for Address Register.

[DevsArchive]

Ah, I didn't see that thread before, completely flew under my radar somehow. Glad to know.

[ekeeke]

REG X002 test 0x03 and WORD RAM test 0x20 fixed by 6cc8bbc (intially fixing issue #482)

[ekeeke]

REG X002 test 0x2B fixed by 6669d25

[ekeeke]

CDC INIT test 0x04 and CDC DMA3 test 0x02 fixed by b330eb8

[ekeeke]

all CDC REGS tests fixed by fcb6620

Note: Wondermega M2, X'Eye, CDX or Multi-Mega BIOS is needed for these tests to run OK (with real hardware, these tests only pass on these models, cf comments above)

[ekeeke]

CDC FLAGS test 0x22 and CDC DMA3 tests 0x04 & 0x13 fixed by 52b4f78

[ekeeke]

CDC REGS tests and REG 2006 tests 0x02, 0x03 & 0x05 (when run as CD BOOT ROM) fixed by 02c9dac and d4ca576

[ekeeke]

CDC DMA3 tests 0x20 and 0x21 fixed by 16589b5

[ekeeke]

CDC DMA3 tests 0x42 to 0x55 fixed by da8e4e5

[ekeeke]

CDC DMA3 test 0x56 fixed by 2c1a2d0

[ekeeke]

CDC DMA3 tests 0x60 to 0x63 fixed by 64d3e08

[ekeeke]

CDC FLAGS tests 0x26 and 0x27 fixed by 90c9c73
CDC FLAGS test 0x30 infinite loop fixed by 79bd0e7 (also makes VAR TESTS 0x02 and REG 8030 test 0x07 returning more realistic measured timing values)

[ekeeke]

CDC FLAGS test 0x30 fixed by 904613f
CDC FLAGS test 0x40 infinite loop fixed by e8a6086

[ekeeke]

VAR TESTS 0x02 and CDC FLAGS tests 0x40/0x41 fixed by 47761b9

[ekeeke]

CDC FLAGS test 0x42 fixed by f09c973

[ekeeke]

CDC FLAGS test 0x46 fixed by 49a289d