-
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 ... -
A Yankee in IraqI'm testing the game on the zx next and it currently hangs right after the game starts no matter what timing regimen and contention pattern is chosen…
... the 48/128 timing model, the extra i/o contention caused by ... port 0x40ff is causing the ula bytes to be missed in ... to avoid the i/o contention, the game runs. So I ... look into the i/o contention in more detail. -
Raster effects - quick questionHi Guys Just a quick question regards what the ULA is doing as its drawing each scan line. Assuming the beam has finished drawing the border, am I…
... a 128), but the ULA interference slows this down.< ... they start relative to the ULA contention pattern, and at exactly ... But in many cases the contention pattern actually helps you synchronise ... the interrupt for perfectly accurate timing, because if the interrupt ... -
How do emulators make code appears as running at 3.5Mhz?Decent Z80 emulators on github return t-states after executing an instruction, giving you the ability to emulate Speccy relatively well. But there ar…
For the ULA and accurate screen updates - just ... implementing contention accurately, all will be well.
For frame timing ... will not give you accurate timing (you want 20ms per frame ... -
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, …
... promise:
[code]
contention btime btime stime stime atime ...
* There is no contention on Pentagon - in this case ... measured relative to when ULA starts asserting INTREQ, that ... in so called late timing, even though one could ... -
Fuse/SPIN vs Spectaculator border timingsHello, I'm trying to figure out at which moments the 48K ULA samples the current border color into its internal latch. To do that I wrote a small …
... able to simplify his Harlequin contention model.
Later on ... , we have nailed the sampling timing of +2A/+3 machines. At ... the INT happening, rather than ULA asserting INTREQ. Which is 1T ... -
If Sinclair computers had not been sold...I was just having a random thought. If Sinclair Computers (or the rights to them, not sure how it 'worked' back then) had not been sold to Amstrad…
... /> [list][*]The I/O contention logic was broken. This was ... ’ ‘fix’ activated the memory contention logic overriding the broken I ... /O contention logic.
[*]A further problem with the ULA I ... 128K machine.
[*]There are timing delays, so that when a ... -
Were the full Sinclair Loki specs ever actually known?I was just curious. A lot was leaked to the media, but the exact specs seem different depending on source. Some say it could support up to 512x256 an…
... was just get the memory contention circuitry to override the faulty ... I/O contention circuitry. They did not fix ... Yet another fault with the ULA design. Because the computers obviously ... 128K ULA. This is also the reason why the video timing is ... -
More "What could have been"... The Z280.So in chasing up the Loki specs, I happened upon some parallel developments... And had Sinclair gotten to make the Loki, there could have been some i…
... other peripherals.
Video timing would go a little funny ... create a suspended clock for timing consistency, and then the coprocessor ... at 3.5MHz with bus contention, for full compatibility or at ... would replace much of the ULA. It might not be too ... -
Emulator compatibility with real SpectrumHi emulator programmers... Having spotted for the last 6 months that my iPAQ is still missing a Spectrum emulator I started typing last tuesday - an…
... put more effort into the timing of the emulated computer (I ... is slower because of the ULA)?
Or must I ... -
WANTED: 128k+ or 128k +2(early grey mod.) ULA chipHello, Attempting to repair my 128k+ speccy. Needs a ULA(IC1)chip from either a 128k+ or an early +2 will work also. If anyone has this chip or has a…
... 128k+ speccy.
Needs a ULA(IC1)chip from either a ... 's broken(other than the ULA), please give me a shout ... -
TimingHey All, Is their away of obtaining timing information on ZX128k other than addresses 23672->23674. Basically I would like to identify every 100th …
... /> Is their away of obtaining timing information on ZX128k other than ... -
Strange layout of Spectrum video memoryHello, does anyone have an idea why the Spectrum's video memory has such a strange layout? I understand that a resolution of 256x192 is an easy mean…
... the inner workings of the ULA can comment on this.
timing etc., I quickly arrived at ... -
ULA schematicsHi everyone. Some while ago I remember getting hold of some circuit schematics of the innards of the Speccy 48K ULA. Sadly I've since lost the files…
... innards of the Speccy 48K ULA. Sadly I've since lost ... -
ULA?Just curious, what does ULA stand for - I'm guessing Ultra Large (Gate) Array?
Just curious, what does ULA stand for - I'm guessing Ultra Large (Gate) Array? -
The ULA and ScreenI've asked something similar before but please bear with me. I'm trying to understand the way the screen is controlled. The ULA controls output to …
... is controlled.
The ULA controls output to the the ... need to change the ROM,ULA and add more RAM ?? or ... -
Z80 cycle contentionHi, Does anybody knows exactly when the ula halts the Z80 clock during a memory r/w cycle? I mean which Z80 clock cycle, T1 or T2? Thanks..
Hi,
Does anybody knows exactly when the ula halts the Z80 clock during a memory r/w cycle?
I mean which Z80 clock cycle, T1 or T2?
Thanks.. -
sound input causing dead ula in +2 ?I have a dead +2a (it shows static black screen, no border see: [url="http://www.worldofspectrum.org/forums/viewtopic.php?topic=9619&forum=4)"]http:/…
... /> I started to think why ula suddenly broke. 'Deadth' posted ... connected tape leads can damage ula.
Also found ... 1b652469b2ff16c9?lnk=st&q=ula&rnum=18#1b652469b2ff16c9"]http ... 1b652469b2ff16c9?lnk=st&q=ula&rnum=18#1b652469b2ff16c9[/ ... -
Memory Map/ContentionHi I'm new to speccy coding (well I did some z80 coding a few years back - like 20yrs ago :) ), and I'd like to get back into writing some scrolling…
... a correct map for memory contention?
Address Size Area ... -
ZXSpin 0.61 Available nowHi all! Well, after a lengthy few testing cycles, I'm taking the plunge and uploading the latest version of ZXSpin, to replace the rather aged old 0…
... much more accurate "ULA snow" and IR contention. Note that truly accurate ... -
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…
... emulator with reasonably precise T timing and with enough speed to ... lines at the times the ULA would read them. It looks ... -
Faulty M1 linesI'm sure this has been discussed before, but using the forum search for the word 'M1' pulled back no hits, which surprised the hell out of me. Anywa…
... can't go looking for timing issues with M1 (for the ... shows it coming from the ULA. -
ULA chipHi. Where i can find a ULA 6C001E-6 chip for an 3B issue Speccy ? Also looking for one 7805 heatsink... Thank
Hi.
Where i can find a ULA 6C001E-6 chip for an 3B issue Speccy ?
Also looking for one 7805 heatsink...
Thank -
UlaI remplaced an ULA 6c001-6 by an ULA 6c001-7 chip on issue 3B board. It is "crucial" to remove R32 and adding the 2x NAND gates ??? or not ? Thanks.
I remplaced an ULA 6c001-6 by an ULA 6c001-7 chip on issue 3B board.
It is "crucial" to remove R32 and adding the 2x NAND gates ??? or not ?
Thanks. -
Fuse for Mac OS X beta releasesA beta version of Fuse for Mac OS X has been released at the dedicated sourceforge project: [url]http://sourceforge.net/projects/fuse-for-macosx/[/u…
... support (Stuart Brady)
[*] Fix contention for LD?R, CP?R ... , as the +2A/+3 ULA applies contention only when MREQ is active ... -
Spectrum ULAHi new to forum ,and have been a speccy owner/fan since the begining{like most 30 somthins on this forum !) Anyway what i want to know is the ULA th…
... want to know is the ULA the same from issue 3 ...
