*** M E M O R U M ***

Great. Thanks again for the feedback.

Changes:

- Added nop's between vdp address and write, as you suggested
- Increased the file size by 4 bytes to 20996

That's the MSX package ...

Whoops. They both start with M and end with X.

I've given the new MTX version a try (alas no MSX kit here to try the other) the results unfortunately are the same, corruption on the loading screen and in the game display itself.

I've found another couple of code sequences that could cause timing issued on the MTX: and the similar INI : JP NZ seqence a few bytes later.

For both OUTI and INI that's a 26 cycle loop on the MTX (as there's no wait states) and at 4mhz it's 6.5us. So those too might benefit from 2 NOPS to extend the access separation past 32 cycles/8us.

Thanks again for your help. I didn't consider the CPU being at 4Mhz would change the vdu timings. I'd optimized the code for the 3.5Mhz MSX CPU.

I've added a few more wait states around the vdu decompression and copy routines.

If using the latest version of MEMU, try using the -diag-vid-time-check option to check the timings.

Success

Looking good !

@under4mhz, I've taken the liberty of posting a copy on my website too - I hope you don't mind?

For the purposes of crediting you with the game, would you like your real name shown, or are you happy with the "under4mhz" handle?

http://primrosebank.net/computers/mtx/m ... dl.htm#new

regards
Dave

Bill B wrote: ↑08 May 2021 12:07 If using the latest version of MEMU, try using the -diag-vid-time-check option to check the timings.

Thanks, that will be useful.

Yes, I'm happy for you to add it to your website. The handle Under4Mhz is fine.

Thanks for your help.