CPS1 Varth Suicide repair?

[Dave_K.]

I am new to this CPS1 suicide thing, and have read the Dead Battery Society page. Unfortunately there is no info/eproms listed for JPN Varth. Anyone know what eproms would need to be replaced along with the +5 fix they describe?

[Ex-Cyber]

I'll look into this at some point if nobody else volunteers (ping me via PM if I forget). At first glance the patches don't look too terrible, but I don't have a disassembler handy to see what they're really doing. The relevant ROMs on JPN Varth would be:

Code: Select all

ROM_REGION( CODE_SIZE, "maincpu", 0 )      /* 68000 code */
ROM_LOAD16_BYTE( "vaj_36b.12f", 0x00000, 0x20000, CRC(1d798d6a) SHA1(b12579e9dcb88416bc00653b143832d9347adbaf) )
ROM_LOAD16_BYTE( "vaj_42b.12h", 0x00001, 0x20000, CRC(0f720233) SHA1(2d9442ceafd5e2208aa8cd4bcb66861bff6aec47) )
ROM_LOAD16_BYTE( "vaj_37b.13f", 0x40000, 0x20000, CRC(24414b17) SHA1(6c0b24cf8045fc033217c737dba2c046d7d0a09a) )
ROM_LOAD16_BYTE( "vaj_43b.13h", 0x40001, 0x20000, CRC(34b4b06c) SHA1(3033d1d053ba97d6da17064d7b944a10817b93b1) )
ROM_LOAD16_BYTE( "vaj_34b.10f", 0x80000, 0x20000, CRC(87c79aed) SHA1(bb90720d1d04ed6ad276a5230cb078229aa8a40a) )
ROM_LOAD16_BYTE( "vaj_40b.10h", 0x80001, 0x20000, CRC(210b4bd0) SHA1(15771c32af9fb4760953ef5475de228200851b42) )
ROM_LOAD16_BYTE( "vaj_35b.11f", 0xc0000, 0x20000, CRC(6b0da69f) SHA1(5883bea31a22a44ad7494d6acd523c88b62f8743) )
ROM_LOAD16_BYTE( "vaj_41b.11h", 0xc0001, 0x20000, CRC(6542c8a4) SHA1(5f828cf28ef905e4701c92f317e1257a40964a65) )

From the filenames and what was said about other boards I assume these would be labeled 34, 35, 36, 37, 40, 41, 42, and 43. It's possible that only some of them would need to be replaced, depending on where the patches need to be made.

[Dave_K.]

Well the board only has 9 eproms, so hopefully I don't have to replace 8 of them.

Appreciate the help though.

[Ex-Cyber]

I think I see what's going on now, more or less. Rewiring the board causes the CPS-B register layout to go to a standard non-suicide one, and then it's just a matter of patching the game to use the "new" CPS-B register addresses (which are nicely laid out in src/mame/video/cps1.c). What threw me is that it also changes the order of the layer enable bits, so I was seeing the bit number arguments in BSET instructions on RAM being patched and thinking "wtf?". But now it all makes sense...

[MKL]

Well the board only has 9 eproms, so hopefully I don't have to replace 8 of them.

I think your Varth is the 2nd run, released on the jedec-eprom B board (like other titles such as Daimakaimura, Strider, etc.):

http://img573.imageshack.us/img573/8320/varth.jpg

The program roms that need to be patched are 22 and 23 (4Mbit each).

The MAME JPN romset (the one Ex-Cyber refers to) is a dump of the 1st run board that had this kind of layout:

http://img59.imageshack.us/img59/7140/13750000.jpg

Here the program roms are 34, 35, 36, 37, 40, 41, 42, 43 (the 8 eproms in the lower right corner), 1Mbit each and equivalent to the two 4Mbit eproms on your board. Note that the empty sockets 24, 25, 26, 27, 28, 29, 30, 31 on your board could be used for these 1Mbit roms as an alternative to 22 (= 24, 25, 28, 29) and 23 (= 26, 27, 30, 31).

So it appears that your version has not been dumped yet.

[Dave_K.]

I think your Varth is the 2nd run, released on the jedec-eprom B board (like other titles such as Daimakaimura, Strider, etc.):

http://img573.imageshack.us/img573/8320/varth.jpg

The program roms that need to be patched are 22 and 23 (4Mbit each).

Yep thats the one I have.

So it appears that your version has not been dumped yet.

So I guess its time for me to invest in an eprom reader/burner?

[Ex-Cyber]

And here I was thinking that he said it had 9 EPROMs because it was 8 for the 68K program, 1 for the Z80 program, and samples/graphics were on mask ROM.

Is the date 920714 or something else? I wouldn't be surprised if it's the exact same program, just interleaved into larger chips.

[Dave_K.]

Where would I find the date?

[Ex-Cyber]

Where would I find the date?

It should show a screen when it starts up like:

VARTH
( VARTH )
920714
JAPAN

More importantly, it would be good to verify that it does actually use a CPS-B-21 chip. I think this chip is on the C-board, but I'm not sure; the Dead Battery Society page has a picture of it, but it's a cropped close-up.

Oddly enough, according to MAME the overseas versions of Varth use CPS-B-04 (the same CPS-B chip used by USA versions of Final Fight). Maybe they were factory-converted Final Fight boards, and that's why they don't have suicide batteries?

[Dave_K.]

I can't read the screen, due to the suicide, its all dark with barley any pixels. So no clue what the program date is, unless someone else has another later JPN version they can confirm with?

[Ex-Cyber]

Ah, I should have realized that, since all graphical roads pretty much lead to CPS-B. It looks like there's a good chance that a suitably interleaved/concatenated version of the MAME set would work, even if it's not guaranteed to be the same revision you're running now. Patching MAME to load the set in such an organization is no problem, but I'm not enough of a CPS1 guru to guarantee that I wouldn't miss something important that might affect compatibility with your board. I'd basically be trusting MAME to hit me over the head when necessary.

Anyway, I'm willing to try it if you are; I just thought I should give you fair warning.

[Dave_K.]

Either way, I'll need to order a programmer if I'm going to test this out. So we might as well just wait until I can dump these two eproms to see if they are indeed interleaved/concatenated or not.

Since I'll be traveling I probably won't have the rom dumps for couple weeks, so I'll update this thread again at that time.

Thanks again for the help!

[caincan]

i forgot this deadly thing. seems i purchased a japanese one. (or by luck the plastic protection is original and game is usa...)

[Dave_K.]

Thanks for reminding me about this thread. I still have not bought my rom burner/dumper for this project.

Hopefully yours turns out to be USA or maybe already de-suicided.

[caincan]

so i have a Jap one. voltage is at 2,8v now ... it's said that < 2v suicides it..

searching hints : he succeeded saving his Jap varth he said by reprogramming PPU chips ?! , but got none answer how.. or how much he charges

some of his other works, http://retrogamebay.free.fr/?capcom-pla ... cps-1.html

_
there's this forum too, http://newlifegames.net/nlg/index.php?topic=155.30

but cant validate to connect and ask the "guru" of these revivals.. (Varth is not on the list as everywhere...) ,

some people know how to reprogram a Jap Varth, but they do it as USA version.. dont know too how they proceed, mame dumps ? , there's still this mod needed.. but i guess it's not the only thing needed..