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PGM Diag/Test BIOS

GC8TECH

GC8TECH

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Hello All,

When going through all my PGM gear to dump version not in mame... I found the BIOS of the "Road Of The Sword" isn't like the default PGM BIOS. It has a lot more error messages and can boot a MoBo even when the stock BIOS won't.

This should be really handy for people working on faulty MoBos. I'm NOT the first to dump it...BUT just wanted to share this info with everyone! I call it the diag bios...

Not sure if i'm allowed to post the file here?? You just need to burn it into a 27C1024. Socket the bios on the MoBo or Pop it in a already socked MoBo.

Tim.
 
djsheep said:
If this happens, would I be able to burn the EPROM to use in my DDP3 cart?
Click to expand...
It would be set up like Ketsui or Espgaluda, so would require an unencrypted base card. I ordered a batch of EPROMS, so will be able to answer once they arrive.
 
A quick update: Good news and "bad" news.
"Bad" news: The SHA1 hash matches https://github.com/mamedev/mame/blo...2256ce07cb9dac/src/mame/drivers/pgm.cpp#L3693
So while it is a new bios that is different from the v1 and v2 bios commonly used in mame, it isn't a completely new one.

The good news: I was able to attach it to a DDPDOJ-DUAL program ROM and boot straight into the game, without the PGM boot/splash sequence.

Making one is quite simple: If you open the ddp program ROM you'll notice that only the first 2MB contain data, the rest is 0xFF. A 27c322 is 4MB, and the base address for games is 1MB. You can simply shift the game inside the EPROM to fit both the bios and the game...

So:
- you'll need a donor cartridge for Espgaluda or Ketsui style games. (I am using my replica PCB with the "generic" U5 pal and 4MB mode.)
- You need to mod the PAL or change the wiring to pass both A19 and A20 through from bus to EPROM unchanged - usually people tie A20 low or high depending on which game they converted.
- The pal needs to always de-select the built-in BIOS and select the EPROM for the full 4MB range. For my U5 PAL I just needed to set JP3 to enable 4MB mode.
- copy the BIOS into a new file, and expand it with 0xFF to 1MB
- decrypt DDP3 and append it, expand with 0xFF to 4MB

If you open the final result in a hex editor it should have the bios at 0, DDPDOJ original at 1MB, DDPDOJ black label at 2MB and 0xFF from 3MB to the end.

I'll try to play the game a bit tonight in case there are incompatibilities with the BIOS. It may be worth putting the motherboard BIOS into a socket to try it with other games...

Edit: Only played the first level and the start of level two - seems to work ok. Probably needs more checking to verify that high scores work. It's a bit late, and I've got work tomorrow.
 
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