... got the ULA timing 100% right. We know when the contention pattern starts ... reliable information about when the ULA actually fetches the screen bytes ... uses early or late CPU timing, please run the btime test ...

... boot, no INK change) so ULA contention issue would surely make black ... , MDA demo (thats gorgeous using ula timing to mask out half of ...

... changed, and there will be contention somewhere. That's all.< ... 4) is timing for muliticolors same like on old ULA (medium priority ... See 2.
4. Standard ULA timing will not change, as a ... be at exactly that moment (contention excepted), or very shortly ...

[QUOTE=aowen;405624]he original ULA has been replicated with 100 ... demand without affecting the normal ULA timing. Thankfully memory is fast ... means running the new ULA at much faster than ... too. Currently documenting the CPU contention, which is proving tricky ...

... />
The difference is contention and timing, etc, are behaviours that emerge ... does because of how the ula manages access to memory for ... actual circuits used by the ula are more or less ... azesmbog's test program. The ula tests except fpga48all works on ...

Multicolour (which created via ula timing, not screen switching) is the ... only functional effect that ULA can do. It's the ... .

But it's timing dependant structure stricts their use ...

... with Speccy due to different ula timing and other small differences. You ...

... 'dead bug' mod to the ULA timing - though a very few early ... 2's used the same ULA so also had this mod ...

... used for researching the updated contention and timing information in the latest ...

... put it down to a ULA timing problem - I remember both Andy ...

... case, this could mean faulty ULA chip (ferranti socketed chip, IC1 ... board since there's some ULA timing issue that was (apparently) never ... and not bother replacing the ULA, which you'll only get ...

... /> However, aiming for a "perfect" ULA timing, I intend to use an ... actual speccy ULA, which likes to output switched ...

... ]However, aiming for a "perfect" ULA timing, I intend to use an ... actual speccy ULA, which likes to output switched ... . Note that the Spectrum's ULA actually exceeds the maximum refresh ...

... , memory location (and maybe contention and timing too, if possible), without having ...

... , memory location (and maybe contention and timing too, if possible), without having ...

... get the port issue sorted - contention information (with high accuracy) will ... know how this will affect contention. ULA contention on even ports is complex ... (back and forth between ULA+ and normal ULA mode) on a frame ...

... choice. Similarly, if there are timing issues with changing the palette ... learn and work with the contention and timing, and just trust that ...

... ?

Thank you,[/QUOTE]ULA timing problems. It is original from ...

... used to improve ULA timing. It is important that ULA 6C001-7 or ... have always understood that this ULA needed the added delay. But ... delay (circuit) needs the new ULA....
Still a 6C001-7 ...

Service Supplement No.1 says regarding Issue 4A: "Two spare gates from IC24 have been used to improve ULA timing. It is important that ULA 6C001-7 or later () are used in this circuit".

... really just be down to ULA timing. I gonna run some tests ...

I can only assume its not emulating some form of ULA timing ( not my area :-? ) accurately. Would contended vs uncondended memory be an issue as the 'real' machine has it emulators might not emulate it accurately.

... precision emulation setting (floating bus, contention, interrupt timing)
- Added NTSC 48K ...

... (ZXMAK2) uses correct +2A/+3 ULA timing :)

... in NIRVANA, because lack of contention affects timing (it runs faster during ...

... NIRVANA, because lack of contention affects timing (it runs faster during ... for ZX-Spectrum models use contention to "re-synchronize" with ... since there's no contention that could be used ... re-synchronization". Luckily, lack of contention makes it run faster, so ...

... RAM before and as the ULA timing is more critical than the ... have been when an older ULA was tried in a later ...

... and test your Spectrum, memory ULA timing, etc.

Work with ...

... in programs which were testing contention and timing details, it was super ... are not affected by bus/contention under any circumstances.