Small DoM Update

So I noticed I neglected to update DoM with the mono 4B games I had already dumped. I did so now. All redumps are in as well as new entries for 4B-001, 4B-004, 4B-006, 4B-008. I updated the last Sachen post as well.

Maybe a bit more info on color Sachen games. As mentioned in the earlier blog post, BigFred and I weren’t sure how to handle 4B Color games yet, so I held off putting them into DoM for the time being. BigFred being a no-intro High Council member and all 😉

In other related news: I now own three Sintax games:

• Zauberringkönig II
  (A Lord of the Rings – Two Towers rip-off)
• Donkey Kong 5 – Die Reise durch die Zeit
  (Donkey Kong 5 – The Journey through Time)
• The Incredible Hulk
  (Graphics hack of Lao Fuzi Chuanqi)

Currently looking at the logo switch code. It’s all complicated by the fact that Sintax connected the full GEC¹⁾Game Edge Connector. (ok, sans PHI and AIN) to their mapper.

Judging from the information I gathered from taizou’s hhugboy (a fork of GEST with support for mappers of unlicensed games) and personal correspondence, Sintax also implemented a bizarre copyright-scheme of bit-swapping and XORing the ROM data and sure enough, the mapper has a dedicated data bus for the ROM.

My initial tests however uncovered two things:

• Sintax’s logo switching is buggy and switches logos one byte before the last logo byte is read, resulting in different logos on DMG and CGB. CGB is lucky in that the Sintax logo and Nintendo logo both have the last low nibble at 0xF. It’s the upper nibble that changes between DMG and CGB (0x3 vs 0x1).
• Sintax do seem to switch the complete logo (RA7 trick, like Sachen, more elaborate though), so they didn’t really need to keep the upper “Nintendo” part. Maybe there’s another bug where the upper part is switched back every second byte that I just haven’t uncovered yet?! Gotta get those oscilloscope traces 🙂

A gallery of popular logos follows: