Sinclair ZX80 / ZX81 / Z88 Forums

This is DSTAR without NOPs added. dstar_crashing_on_zxpandplus.p.gz I think in my original driver I've put an even longer delay block, by the way here's the current fix wit a single NOP I'm using in the updated driver. dstar_extra_nop.p.gz They are built with the "BREAK" feature, it means that if yo...

The ROM entries I'm using at the moment: $29B - Other drivers use $29E only. Save blank lines, start NMI, POP registers and RETURN $29E - Update A', start NMI, POP registers and return to BASIC/programs $220 - PUSH register, then do VSYNC and get KEYBD $2A2 - Enable the NMI generator and return to t...

Well, if the picture is showing correctly in both the cases, we are going in the right direction. The sampler includes something running in 64 rows mode. I noticed that for some reason the interrupt timer runs twice faster which could mean the driver is refreshing at doubled rate when in 64 rows mod...

the wrx driver relies on ROM routines, it could be that something is different on the improved ROM. @Paul, I will provide a build with and without the NOP. Oddly it was only DSTAR crashing, and only in full screen mode. The BREAK feature is rather subtle, you probably can't experiment it on the exam...

While compiling test programs I thought a sampler archive was a nice thing to have

EDIT: 2 more teasers I got having fun during the tests.

While testing the new driver I noticed that DSTAR crashes in 192 rows mode unless I add at least one NOP instruction.
I'm not sure whether the crash is caused by a memory alignment problem or timing/sync issues, other programs run smoothly on EO.

I'm also wondering what the 128 char mode is.

Thank you. Could you test both the programs? They seem identical but one of the two includes a break keys detection

Yet another prototype. Am I getting closer?

Ok, I'm trying to merge in the Paul's code, but honestly I'm doing it mechanically, replacing the existing code portions with the new ones. I haven't identified the code changes permitting the better control of the picture sync, and the 64 rows mode is temporairly lost (on my prototype) but it is so...