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Gyruss diagnostic roms
#251264 - 04/08/11 10:52 AM
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Hello,
While reading the gyruss driver, I found a reference to diagnostic roms, however they are not referenced in the rom set.
Do they exist, and if they do, where can I find them ? They would be very helpfull for me to fix a gyruss pcb with faults on sprites. Actually, all sprites are missing after power up.
Since the konami-1 cpu is custom, I cannot swap it with a regular 6809. Also, the board suffered from corrosion which I cleaned up the best I can.
thank you
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Re: Gyruss diagnostic roms
[Re: alca]
#251265 - 04/08/11 11:26 AM
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> Hello,
>
> While reading the gyruss driver, I found a reference to diagnostic roms, however they
> are not referenced in the rom set.
>
> Do they exist, and if they do, where can I find them ? They would be very helpfull
> for me to fix a gyruss pcb with faults on sprites. Actually, all sprites are missing
> after power up.
> Since the konami-1 cpu is custom, I cannot swap it with a regular 6809. Also, the
> board suffered from corrosion which I cleaned up the best I can.
>
> thank you
AFAIK neither the main diagnostic nor audio cpu diagnostic roms have ever been found or dumped. We just know where in the memory map they WOULD be.
The subcpu konami-1/6809 runs at 2mhz clock input, correct?
LN
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"When life gives you zombies... *CHA-CHIK!* ...you make zombie-ade!"
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Re: Gyruss diagnostic roms
[Re: Lord Nightmare]
#251266 - 04/08/11 11:38 AM
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Okay  Yes, the Konami-1 cpu runs @ 2 Mhz. However the chip package has extra pins, so I cannot replace it with a regular 6809. Also, as far as I know based on mame source code, the konami-1 cpu is a regular 6809 with some scrambled lines. However, I don't know yet if only the opcodes are scrambled or data also. If both data and opcodes are scrambled, it should be pretty straightforward to descramble it.
Also, the sprite hardware uses 4 sram with unknown yet reference, so I cannot test them.
The worst is all worked perfectly a single time yesterday.
Then after powering-off and powering-on again, I got the same problem: sprites missing.
Maybe it is related to bad synchronization between the two cpu (z80 and 6809), or bad reset. But the reset seems to work ok as far as I have tested.
Next step will be to test the 2x27C245 and 2x27C244 used on the konami-1 bus and also the 2128 ram which is soldered.
Any information / help appreciated 
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Re: Gyruss diagnostic roms
[Re: alca]
#251273 - 04/08/11 02:17 PM
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Opcodes are encrypted, data and opcode operands are not.
I have successfuly decrypted the program rom for gyruss konami-1 cpu.
I can make it available for the people who need it if they want to use a regular 6809.
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[Re: 
Yes, the Konami-1 cpu runs @ 2 Mhz. However the chip package has extra pins, so I cannot replace it with a regular 6809. Also, as far as I know based on mame source code, the konami-1 cpu is a regular 6809 with some scrambled lines. However, I don't know yet if only the opcodes are scrambled or data also. If both data and opcodes are scrambled, it should be pretty straightforward to descramble it.
