MiSTer FPGA Forum

Hi Everyone!

I'm trying to play 'Mad Mix' in the ZX Spectrum core, but all versions of the game (Erbe, Ibsa, The Pepsi challenge) be it the tape or disk version, show corrupted graphics on the screen. I tried loading it in 48K and 128K mode and also changing some of the options of the core with no success.

Does it work for you? Any suggestion for compatible settings?

Thanks!!

Cheers,

Same here. Could well be a core bug.

...later on, I loaded it in Spectrum Next core via tzx. It worked, though the playfield itself was black & white. Odd.

The corruption is caused by the game writing to port FFh. This same corruption is reproducible in FUSE by selecting TC2048 as machine. So I suppose that the problem is that there's no way to disable TC2048 compatibility in the core.

A software fix is to replace all occurrences of D3 FF with 00 00 (there should be three of them). This affects the xorsum at the end of a TAP, though, but it should work on a disk version.

Edit: By the way, it works perfectly fine for me on the Next core (using a TAP version). I can't reproduce the B&W playfield issue.

Hi pgimeno,

I followed your advise and edited my dsk file in an hex online editor; there were exactly 3 instances of D3 FF and I replaced them with 00 00. Loaded again and now it works great!

Thanks for your help and detailed explanation!!

Cheers,

I said:

pgimeno wrote: ↑Mon Jan 03, 2022 1:04 pmSo I suppose that the problem is that there's no way to disable TC2048 compatibility in the core.

I stand corrected. In the Hardware page, changing Port #FF from Timex to SA1099 fixes the issue.

Just tried to change the #FF port setting to SA1099 and it also fixes the issue, thanks!!