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Brazilian TK90X and TK95SpecEmu provides explicit support for Brazilian TK90X. Other emulators provide indirect support (perhaps the "Spectrum 48K NTSC" option in Fuse?). Al…
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Contention on Spectrum 48K with "normal" timing should start at ... T cycle 0 is when ULA starts generating the interrupt pulse ... one cycle later). As contention is ULA related thing and not CPU ... his excellent research on the ULA, it became more common ... -
Some thoughs about fast scrolling on 128 modelPlease, consider this article as technically interesting concept not a proven algorithm. ONE The fastest scrollers use long sequence of PUSH inst…
... ]14335[/B]. The instruction timing table indicates this instruction behavior ... a little if the ULA is using the bus ... easy to avoid the first contention (related to instruction location) ... instructions are affected by contention from referenced address more than ... -
ULAs interchangeable across issuesHi all, Now that I'm retired, I'm looking again at 8 bit computing :) I'm attempting to revive a spectrum 48K. I'm going to swap chips in/out from…
... a 6C001E-7 ULA. This is due to timing changes introduced on ... there to fix overly aggressive contention when accessing I/O ports ... a 5C102/112/6C001E-6 ULA on a Issue 4A and ... -
Hardware description - MB-02+ interfaceOn this thread will soon released info about MB-02+ idisk interface ( memory paging mechanism, list of ports, addressing, MB IDE, schematics, etc... …
... as main Z80CPU. But timing of reading/writing bytes is ... block from ZX ram to ULA port #FE = multicolor ... to videoram(slow ram) ULA chip slow down DMA ... is slow down by ULA chip but is faster ... little and +2A/+3 ULA use different memory contention)
... -
LOOK at the size of my Rom/EmulatorOk, we have 16k, 48k, 128k, even a 256 odd k Rom/Emulator But I want more :p Is there anything out there now or been worked on to give more, as the…
... infamous doohickie referred to as [timing] "contention" all aboot, eh?
< ... hardware).
Can contention be done away with in ... />
Contention is due to the fact the ULA and the ... the same time so the ULA gets preference, this slows ... -
Two more faulty onesCould I get your opinion on these two faults, please? Understanding these two cases would be very beneficial for my ZX education. Thanks! - A Spectr…
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The ULA cleaned up the earlier I/O contention fixes that ... had been applied to the issue 2 5C112E ULA ... and altered the timing of the colour ... =1]Chapter 24. ULA Versions, section "Issue 3 ULA 6C001E-6", p ... -
48k+ ULA'sI've got three ULA's here that only work in certain boards. Thought I was going nuts, swapping, changing stuff around. But hey, I've got two working …
... versions of the Spectrum 48K ULA:
[LIST]
... . Have a I/O contention fault that necessitates the ' ... version, alters colour burst timing for increased compatibility with certain ... on the timing changes incorporated into the 6C001E-7 ULA.
... -
New test for finding missing +2A/+3 ULA timing detailsHello, having added the +2A/+3 emulation recently, I want to make sure I got the ULA timing 100% right. We know when the contention pattern starts, …
... attribute fetch goes unnoticed and ULA always fetches the pixels from ... due to subtle timing differences, or because the +3 ULA intentionally delays ... way how the +3 ULA prepares the screen address on ... not really needed for the contention, it is perhaps just an ... -
48k+ ULA'sI've got three ULA's here that only work in certain boards. Thought I was going nuts, swapping, changing stuff around. But hey, I've got two working …
... versions of the Spectrum 48K ULA:
[LIST]
... . Have a I/O contention fault that necessitates the ' ... version, alters colour burst timing for increased compatibility with certain ... on the timing changes incorporated into the 6C001E-7 ULA.
... -
Totally random idea for the hardware nuts to exploreWhen it comes to multi-player games, how hard would it be to generate a second display from a single Speccy, instead of trying to link up machines, s…
... then the only requisite for timing would be that the vertical ... chip that just emulates the ULA and external RAM is one ... , become contended - would the external ULA/RAM setup be able to ... of the ROM. Could read contention be avoided, such that the ... -
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…
... contention as ULAplus is part of the ULA and the ULA ... which doesn't contend the ULA+ ports...[/QUOTE]
< ... we knew what the contention would be. Although Woody ... software that required precise timing at the time it ... to figure out the timing for HAM256 as I ... -
Spectrum screen layoutSeeing the thread on displacement I was wondering why the spectrum had the stupid screen split into three sections and the addresses for each section…
... reads from memory whilst minimising contention (i.e. either a ... When drawing the screen, the ULA reads four bytes of memory ... constraint imposed by the ULA and the DRAM refresh ... possibly the best — between the timing requirements for burst mode reads ... -
Plea for new hardwareI'm posting this as a poll as I want to judge if I'm a solo loon going on about this, or if people really are interested in either of the following S…
...
In a word contention. I completely missed the fact ... to fake the effects of contention via the clashbasher by ... with an internal ULAplus ULA fitted ie double contention. :o
< ... switched on, super-accurate timing wouldn't really matter all ... -
HDMI generation by cloning video ram(coming from [url]http://www.worldofspectrum.org/forums/showthread.php?p=768257&posted=1#post768257[/url]). A thing I was brainstorming about.. Why …
... video ram reading and contention problems.
Simply ... No more need for a ULA ;)[/QUOTE]
... to synch with the timing.
BUT, if ... ULA plus palette and multicolour, and 128K paging, then maybe the timing ... you do ignore the timing - even if you' ... -
z80 commands timeshi! I need site with z80 commands mashine times. I remember, I saw one as table, maybe in .cc domain, but pity forgot link. for example LDI take 16 …
... shows real instruction breakdown under ula contention, it also teaches you why ... sheet when working under critical timing:
[url]http://www ... -
z80 commands timeshi! I need site with z80 commands mashine times. I remember, I saw one as table, maybe in .cc domain, but pity forgot link. for example LDI take 16 …
... shows real instruction breakdown under ula contention, it also teaches you why ... sheet when working under critical timing:
[url]http://www ... -
Timing_Tests-48k_v1.0 results...Hello All, I ran these [URL="http://www.zxspectrum4.net/op_timing.php"]tests[/URL] on my emulator and some of the tests failed.. so I tried it on a …
... test 35 as long as ULA+ is disabled, and it passes ... spent on figuring out the contention details [URL="http://www.worldofspectrum ... point is to test the contention timing, not the emulation of peripherals ... subsequent INs and thus the timing at all. I guess I ... -
Timing_Tests-48k_v1.0 results...Hello All, I ran these [URL="http://www.zxspectrum4.net/op_timing.php"]tests[/URL] on my emulator and some of the tests failed.. so I tried it on a …
... test 35 as long as ULA+ is disabled, and it passes ... spent on figuring out the contention details [URL="http://www.worldofspectrum ... point is to test the contention timing, not the emulation of peripherals ... subsequent INs and thus the timing at all. I guess I ... -
ULAAre ULA's (for Spectrum 48k's) interchangeable through the different issues? To give some background, to work out what was wrong with an old speccy I…
... boards. Have a I/O contention fault that necessitates the 'dead ... power version, alters colour burst timing for increased compatibility with certain ... on the timing changes incorporated into the 6C001E-7 ULA.
How did bank switching work on the 128K Spectrums?I'm new to Z80 and ZX Spectrum. So I was wondering how the 128+ models managed to work with more than 64K of memory? I'm somewhat familiar with h…
... between the z80 and the ula so a simultaneous access by ... 're trying to avoid contention to run timing critical code or to ...Ninjaman 8-way scrolling 50Hz multicolour demo :-)Here's a demo I've been working on for a while. The goal was to make the best scrolling routine possible on a humble 48K ZX Spectrum. I was origin…
... execute. Too late, and the ULA will already have read in ... the old attributes before the ULA read them.
... to tweak the timing to account for the various contention differences between ... is doing exactly the same timing pattern, but when you start ...ZX Spectrum Sprite chipHi everyone. As I said some time ago, I wanted to make a 'virtual' Sprite chip for the ZX spectrum, on my ZEsarUX emulator. The idea is to make so…
... you aren't replacing the ULA you need to allow it ... account for the timing of doing so and the contention that will ...No contended memory?Sorry if this is a stupid question. But I'm trying to learn more about the ZX Spectrum. If I had a stock 48k Speccy and I could wave a magic wa…
... + is another clone without memory contention.
Given the poor ... RAM) and display issues (128K timing but a ridiculously short gap ... pixels by the ULA), the lack of memory contention was probably about ...7mhz CPU?One of the things I like about Spectaculator, is that I can zap the clock speed of the emulated CPU up. Doing so makes me wonder about why the desig…
... exists). But all the contention and DRAM timing signals would also have ... difficult.
Remember the ULA does a lot of hidden ... high speed.
The ULA chips fitted to later issue ... compatible and using the original ULA chips would have made ...Vega ARM SOC?I read that the core of the new Vega was an ARM SOC. I thought it would have been an FPGA. But it seems it's an ARM running an emulator. Anyone kn…
...
A picture that uses timing techniques to change the border ... the relationship between the ULA and how it affects timings ... the TV. As the ULA repeatly reads the value ... 16384) ;an operation that generates contention
ld a ...Best Z80 Assembler for PC?There's probably already a thread for this so if somebody could please point me at it I'd appreciate it. If there isn't then please respond here wit…
... shared between cpu + ula and only when the ula is accessing the ... have a contention on and contention off mode to do timing with and ... ula is.
So not trivial at all. Unaltered z80 timing ... you can see where the contention delays are. On the ...Correction of +2 hardware errorsThis is a collection of various pieces of information picked up from various places, including a lot from this forum. I have edited it and reworded i…
... RFSH from CPU for eliminate ula effect known as "screen raining ... O ports slow-down CPU (ula slow-down cpu with same ... cause small incompatibility with original timing in some ZX demos...
contention:
[url]http://velesoft.speccy ...Interrupts, 16k Spectrums and snowI'm writing something for the 16k Spectrum and I want to use interrupts. The avilable documentation doesn't seem clear enough for me to figure out ho…
... window every frame when the ULA's drawing the border at ... (and the sides too) where contention isn't an issue.[/quote ... , but it would iron out timing fluctuations up to about 12K ...Send in the ClonesPlease name all the Spectrum clones out there ( I would say I need it back on my desk in 5 minutes , but I will be a bit more generous in this case!…
... the ZX Prism clone with ULA Plus technology support in Australia ... to having no memory contention and different video timing, games which do ...Bit of fun - one change onlyI also posted this on another marque's forum (for their products) to see. Its just a bit of fun really. OK, if you could of made one change to a S…
... hardware and removing the memory contention would give back at ... area) would removal of contention mean the ULA would of had to ... 'added around' to remove the contention, if that makes sense ? :) ... is usually why things like timing critical bits and highspeed ...
