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New Spectrum emulator for DS[url]http://zxds.raxoft.cz/[/url] [quote]Features already implemented: * Solid Z80 core - possible bugs aside, the Z80 emulation is as complete…
... lines at the times the ULA would read them. It looks ... .worldofspectrum.org/infoseekpub.cgi?regexp=^Patrik+Rak$]this guy[/url]... -
[NEW] Retro Virtual Machine v1.0.0 for OSX released!!!!Here it is! Retro Virtual Machine v1.0.0 RELEASED!!!! Many thanks first to Patrik Rak for the PZX format and for their Z80 tests without which RVM…
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Many thanks first to Patrik Rak for the PZX format and ... to pixel accuracy in the ULA emulation.
Tape emulation ... -
Contention and floating bus timingHello, I was recently playing a bit with memory contention and floating bus stuff in ZXDS and there is one thing which puzzles me a bit. It is the d…
[QUOTE=Patrik Rak;213334]Could this be as ... people counting it from when ULA pulls INTREQ low, while others ... -
Contention and floating bus timingHello, I was recently playing a bit with memory contention and floating bus stuff in ZXDS and there is one thing which puzzles me a bit. It is the d…
... different things
[QUOTE=Patrik Rak;213352]Could this be also ... 1T with respect to the ULA [/QUOTE]
Probably. The ... -
Contention and floating bus timingHello, I was recently playing a bit with memory contention and floating bus stuff in ZXDS and there is one thing which puzzles me a bit. It is the d…
[QUOTE=Patrik Rak;213352]Could this be also ... 1T with respect to the ULA.[/QUOTE]
BTW, it ... of for how long the ULA holds the INTREQ low. On ... . Which would mean, assuming the ULA holds the line low for ... over the face).
Patrik -
Contention and floating bus timingHello, I was recently playing a bit with memory contention and floating bus stuff in ZXDS and there is one thing which puzzles me a bit. It is the d…
[QUOTE=Patrik Rak;213973]In fact, I thought ... snow effect happens because of ULA [B]not[/B] applying the ... IR pair clashing with the ULA address put on the bus ... -
Contention and floating bus timingHello, I was recently playing a bit with memory contention and floating bus stuff in ZXDS and there is one thing which puzzles me a bit. It is the d…
[QUOTE=Patrik Rak;214171]Well, if I am ... confident that is what the ULA is also doing.
... get access back and the ULA would continue to read another ... accessing the memory when the ULA is. If we accept ...
I am writing a ULA internals paper at the moment ... -
Contention and floating bus timingHello, I was recently playing a bit with memory contention and floating bus stuff in ZXDS and there is one thing which puzzles me a bit. It is the d…
... =Patrik Rak;214325]
1) The T state 14342, at which the ULA ... -
Contention and floating bus timingHello, I was recently playing a bit with memory contention and floating bus stuff in ZXDS and there is one thing which puzzles me a bit. It is the d…
[QUOTE=Patrik Rak;214325]I have been trying ... state 14342, at which the ULA reads the second attribute from ... -
Contention and floating bus timingHello, I was recently playing a bit with memory contention and floating bus stuff in ZXDS and there is one thing which puzzles me a bit. It is the d…
[QUOTE=Patrik Rak;214336]I have now ... it is because the ULA starts applying the contention ... Wiki[/B]
+3 ULA, which applies less contention ... than the 48K ULA (specifically, it applies ... active, whereas the 48K ULA applies it under all ... -
Contention and floating bus timingHello, I was recently playing a bit with memory contention and floating bus stuff in ZXDS and there is one thing which puzzles me a bit. It is the d…
[QUOTE=Patrik Rak;214373] This way, all M1, ... other cases where the 48k ULA applies contention when there is ... -
Contention and floating bus timingHello, I was recently playing a bit with memory contention and floating bus stuff in ZXDS and there is one thing which puzzles me a bit. It is the d…
[QUOTE=Patrik Rak;214398]Yep, and now we ... least as far as the ULA fetches and memory contention is ... it explains where the issue2 ULA bug appeared from. Investigating.....[/I ... -
Pentagon floating bus timingI wanted to take a little break from working on the ZXDS UI yesterday, so I added support for Pentagon timing instead, so I can finally enjoy the lik…
[QUOTE=Patrik Rak;228409]I wanted to take ... timing. An explanation how the ULA replacement fetches the bytes without ... -
Detecting a Kempton joystick...I've been playing with the idea in the games I'm currently developing so that once the Kempston joystick has been selected you can hold FIRE down to …
[quote=Patrik Rak;239876]Have a look at ... is short enough for the ULA
; not to start fetching ... -
Inside the ULAI've recently updated my Blog with the news that I've managed to get inside a 6C001E ULA and have got close up images of the die. I'm currently back-…
[QUOTE=Patrik Rak;325014]Yeah, I was about ... just got distracted with my ULA research.
Chris -
Data bus at interrupt timeIt is "well known" that some peripherals can put values other than 0xff on the data bus at interrupt time, thus meaning that IM2 is slightly more fid…
... Spectrum's sole interrupter (the ULA) was not designed for working ... these devices attached, the ULA's peripheral id could become ... SCLD peripheral ID, like the ULA ID, could therefore be ... lines.
[/QUOTE]
Patrik Rak would appear to be correct ... -
ZXDS 0.9.0 beta 1Hi! New version of [URL="http://zxds.raxoft.cz"]ZXDS[/URL] is available. Only one important change this time, but the one I have been dreaming about…
(re: new ULA feature)
[QUOTE=Patrik Rak;397700]You mean the one ... -
50Hurts - Full-screen 50Hz 1-pixel scrolling on a 128K Speccy50Hurts - Full-screen 50Hz 1-pixel horizontal scrolling on a 128K Speccy. Graphics are an obvious nod to Joffa, whose games and banter were a big ins…
[QUOTE=Patrik Rak;523790]ZX Spectrum doesn't ... .
I'll check ULA book when I get home ... -
ZXDS 0.9.3 beta 1Hello, Today it's exactly five years since the [URL="http://zxds.raxoft.cz"]ZXDS[/URL] has come to life on my DS. To celebrate this anniversary, I h…
[QUOTE=Patrik Rak;612098]Well, not much, really. ... .)
...
Thanks,
Patrik[/QUOTE]
OK, ok ... interesting are:
1) ULA+ support
2) Microdrives
Great work though Patrik.
Paddy -
ZXDS 0.9.9 beta 1OK kids, here we go: Let me announce the latest and greatest [URL="http://zxds.raxoft.cz"]ZXDS release[/URL]. Mouse emulation, tape recording, stats …
[QUOTE=Patrik Rak;621470]I never had problems ... will automatically start.
Patrik[/QUOTE]
Thanks for ... video or hardware enhacements (like ULA+, or Sam Coupe, or those ... -
Pentagon RAM memoryDoes anybody know or have reference to technical docs, how no contention on RAM access is achieved in Pentagon 128K clone ? Looking at schematics it …
[QUOTE=Patrik Rak;659272] They would even actually ... up quite a bit more ULA real estate, or alternately, need ... -
Pentagon RAM memoryDoes anybody know or have reference to technical docs, how no contention on RAM access is achieved in Pentagon 128K clone ? Looking at schematics it …
[QUOTE=Patrik Rak;659272]So, as I see ... you can simply read whatever ULA needs in one half of ... adjusting the RAS/CAS timings ULA uses to address the memory ... the contention handler of the ULA, and the ULA was full! -
Pentagon RAM memoryDoes anybody know or have reference to technical docs, how no contention on RAM access is achieved in Pentagon 128K clone ? Looking at schematics it …
[QUOTE=Patrik Rak;659446]Why additional latch? The ULA already buffers both video and ... something?
Patrik[/QUOTE]
The ula is already buffering ... -
Pentagon RAM memoryDoes anybody know or have reference to technical docs, how no contention on RAM access is achieved in Pentagon 128K clone ? Looking at schematics it …
[QUOTE=Patrik Rak;659446]Why additional latch? The ULA already buffers both video and ... I missing something?
Patrik[/QUOTE]
Timing constraints ... -
ZXDS 1.0.0Hello, new [URL="http://zxds.raxoft.cz/"]ZXDS release[/URL] is out of the door. Now ZXDS has all the features I have only dreamed about 5 years ago,…
[QUOTE=Patrik Rak;684916]Glad you liked it - ... bear it anymore... :)
Patrik[/QUOTE]
Forgive my ... half so persistent in seeking ULA plus support. ;) -
Pentagon floating bus timingI wanted to take a little break from working on the ZXDS UI yesterday, so I added support for Pentagon timing instead, so I can finally enjoy the lik…
... same computer.
[QUOTE=Patrik Rak;758004]From that schema it ... Lion17 describe (the delay of ULA fetches) sounds much more ... issue.
[QUOTE=Patrik Rak;758004]As for using the ... on?
[QUOTE=Patrik Rak;758004]Indeed, there is no ... -
Pentagon floating bus timingI wanted to take a little break from working on the ZXDS UI yesterday, so I added support for Pentagon timing instead, so I can finally enjoy the lik…
... myself :)
[QUOTE=Patrik Rak;758079]AFAIR, the tests will ... .
[QUOTE=Patrik Rak;758079]What is your explanation ... .
[QUOTE=Patrik Rak;758079]You might not like ... specified T cycle after ULA (or "ULA" in case of Pentagon ... -
Pentagon floating bus timingI wanted to take a little break from working on the ZXDS UI yesterday, so I added support for Pentagon timing instead, so I can finally enjoy the lik…
[QUOTE=Patrik Rak;758728]I still haven't ... at T cycle 17988 after ULA generates interrupt, and change every ... the intended behavior.
Patrik -
Fuse 1.1.1 releasedOn behalf of the Fuse team, I am pleased to announce the 1.1.1 release of Fuse. The changes from the recent 1.1.0 are relatively minor, mostly correc…
[QUOTE=Patrik Rak;767445]Yeah, that's quite ... is part of the ULA and the ULA is contended.
ULA+ ports...[/QUOTE]
Well ... -
Fuse 1.1.1 releasedOn behalf of the Fuse team, I am pleased to announce the 1.1.1 release of Fuse. The changes from the recent 1.1.0 are relatively minor, mostly correc…
[QUOTE=Patrik Rak;767468]You have perhaps ... am not saying that the ULA+ ports should not be ... have preferred that, so ULA+ and ULA would have the same ... contention as the ULA because it is the ULA, regardless of ... the same ... it is the ULA contention.
[ ...
