FS Parts: Burger Time PCB

[Gamer4Life]

I have an untested(assume non working) Burger Time PCB for sale. Board appears to be complete. I does have some type of diy cpu in it. 110.00 plus 15.00 shipping

 

[DogP]

I know this thread is old, but that's pretty interesting... it looks like they replaced the CPU-7 module with a plain 6502. Presumably, the ROMs are a hacked/decrypted version that runs with just a 6502 instead of needing the CPU-7 bit mangling. If anyone bought this, I'd be interested to know what's on the ROMs (ROM hack, maybe a known bootleg like "Cook Race", etc).

DogP

 

[mgkastra]

I know this thread is old, but that's pretty interesting... it looks like they replaced the CPU-7 module with a plain 6502. Presumably, the ROMs are a hacked/decrypted version that runs with just a 6502 instead of needing the CPU-7 bit mangling. If anyone bought this, I'd be interested to know what's on the ROMs (ROM hack, maybe a known bootleg like "Cook Race", etc).

DogP

I have seen a couple projects current and in the past where people have recreated the cpu. My guess is under that board there are some 74's not being shown.

 

[DogP]

You could be right, though I don't think so... looking at how many chips a real CPU-7 has (decapped pic here: https://forums.arcade-museum.com/threads/replacing-the-cpu-7-in-a-burgertime.372464/ ), I don't think there are enough holes in that perf board. I'd think we'd be able to see the legs sticking through too... and why would they put the chips on the bottom of single sided perfboard anyway?

Using the MAME debugger, I think it'd be pretty easy to decrypt the ROMs so they'd run with a standard 6502. At certain addresses the data gets shuffled following a write... in which case you could figure out which addresses those are, shuffle the bits the way they should be there... then reburn those ROMs. I noticed this board doesn't have any original ROM labels, which was another reason I'm curious.

Oh, I really doubt this board works though... it looks to be missing the RAM near the CPU-7 (2128 on my board, though I think it'd work with a standard 6116).

DogP

 

[HudsonArcade]

Using the MAME debugger, I think it'd be pretty easy to decrypt the ROMs so they'd run with a standard 6502. At certain addresses the data gets shuffled following a write... in which case you could figure out which addresses those are, shuffle the bits the way they should be there... then reburn those ROMs. I noticed this board doesn't have any original ROM labels, which was another reason I'm curious.

That's pretty easy to do since only 1/4 of the addresses are even candidates for decryption, and a smaller fraction of them are opcodes.

For my Sega System 1 decryptions, I wrote some C that "executed" code to mark what's code and what's data so the decryption could be more automated. 6502 would be even easier since there aren't any instructions like the z80's

jp (hl)

to complicate things, but there are still coding styles that could make automated decryption tricky.