Tekken 2 Rev.B Error in the existing dump.
- Thread starter pierpa86
- Start date
I took apart three Tekken 2 ROM boards and did more testing.
First board:
At first I didn't notice the IC order issue and just desoldered everything. After comparing with MAME, I found that 1L and 1U on this board were swapped relative to the ROM data. The other chips were too aged to read properly. Then I burned the entire board using 29F chips following MAME's order — it didn't boot.
Second board:
Looking at the silkscreen, the IC numbers didn't match MAME's layout. The pairs were reversed: 1–9, 3–8, 4–7, 5–6. This time I only desoldered IC8 (1L). Comparing it, I found it matched 1U in MAME. So I suspect the first board had the same arrangement.
Third board:
The order was different from the second board again — 1U and 1L were swapped once more. I again only desoldered IC8, but when I read it, it matched neither 1U nor 1L in MAME. The CRC was 8938c48c. I tested it multiple times and found no signs of aging or corruption. I copied this chip to a 29F and it ran fine. This ROM board also has a unique KeyCUS — although the silkscreen says C408 on both, they couldn't be swapped. Swapping the ROM board alone gave an 'ERROR KEY' message on boot.
Conclusion:
The System 11 series has multiple ROM revisions. MAME only documents one of them. For repair or conversion work, always rely on the actual hardware.
First board:
At first I didn't notice the IC order issue and just desoldered everything. After comparing with MAME, I found that 1L and 1U on this board were swapped relative to the ROM data. The other chips were too aged to read properly. Then I burned the entire board using 29F chips following MAME's order — it didn't boot.
Second board:
Looking at the silkscreen, the IC numbers didn't match MAME's layout. The pairs were reversed: 1–9, 3–8, 4–7, 5–6. This time I only desoldered IC8 (1L). Comparing it, I found it matched 1U in MAME. So I suspect the first board had the same arrangement.
Third board:
The order was different from the second board again — 1U and 1L were swapped once more. I again only desoldered IC8, but when I read it, it matched neither 1U nor 1L in MAME. The CRC was 8938c48c. I tested it multiple times and found no signs of aging or corruption. I copied this chip to a 29F and it ran fine. This ROM board also has a unique KeyCUS — although the silkscreen says C408 on both, they couldn't be swapped. Swapping the ROM board alone gave an 'ERROR KEY' message on boot.
Conclusion:
The System 11 series has multiple ROM revisions. MAME only documents one of them. For repair or conversion work, always rely on the actual hardware.