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Yellow issue 4A keyboard madnessNote sure if this is a similar problem to the one CornishManicMiner has, but one of my yellow issue 4A boards is driving me crazy. I had it in variou…
... of the circuit to IC1 (ULA) pin 33 is okay. This ... repeated (using different ranges) IC1 (ULA) pin 33 and IC2 (Z80 ... please.
[I][B]Mark[/B][/I] -
48K: Half of copyright message in the middle of the screen?!Issue two. Has 74LS08 over the Z80, but the ULA is 5C112E-3 (I think this should be a 5C102E??? - I have one, but I'm not sure if it is working, at l…
... (correctly mind) to a later ULA would not cause any problem ... A14 is connected through to ULA pin 36 and address line ... through to ULA pin 37.
[I][B]Mark[/B][/I ... -
48K: Half of copyright message in the middle of the screen?!Issue two. Has 74LS08 over the Z80, but the ULA is 5C112E-3 (I think this should be a 5C102E??? - I have one, but I'm not sure if it is working, at l…
The ULA needs to have address pins ... 74LS00 or 74LS08 to the ULA pins 36 and 37, and ... core wire to link the ULA pin to the PCB track ... D7).
[B][I]Mark[/I][/B] -
48K: Half of copyright message in the middle of the screen?!Issue two. Has 74LS08 over the Z80, but the ULA is 5C112E-3 (I think this should be a 5C102E??? - I have one, but I'm not sure if it is working, at l…
... be absolutely sure.
Mark's right, the cockroach should ... /> The wiring connections from the ULA to the 74LS00 you need ... are:
Pin 36 ULA -> pin 11 74LS00
Pin 37 ULA -> pin 8 74LS00
48k Spectrum ULA issue?Hi All, Have a couple of Spectrums Plus' with their orignal ULAs showing the failure as in screen 2 on the left. [URL="http://hardware.speccy.org/i…
... around (move the known good ULA to the poorly machine and ... move the suspect ULA to the known good Spectrum ... moves, it is a defective ULA. If the fault does ... test, put the good ULA back in the working Spectrum ... chips.
[I][B]Mark[/B][/I]New user with a dead 48k issue 2Hello all I've found my way here from watching some excellent youtube videos by Joulesper Coulomb in an attempt to fix a issue 2 rubber key 48k I bo…
... the Spectrum has a working ULA and a working Z80 CPU ... chip is the ULA then?
[B][I]Mark[/I][/B]New user with a dead 48k issue 2Hello all I've found my way here from watching some excellent youtube videos by Joulesper Coulomb in an attempt to fix a issue 2 rubber key 48k I bo…
... chip is the ULA then?
[B][I]Mark[/I][/B ... ?
Yes only the ULA is socketed.ZX Spectrum Clock Signal Restorer Circuit[SIZE=5][U][B]ZX Spectrum Clock Signal Restorer Circuit[/B][/U][/SIZE] The circuit below is an experimental circuit. It has only been "tested" using…
... about the loading on the ULA clock output. I am aware ... what kind of load the ULA output can tolerate.
ULA and the Z80 CPU.
[I][B]Mark[/B][/I]128+ grey screen faultneed help diagnosing this picture,this is not my machine but a picture found online but this is exactly what i found on this +2grey i just picked up.…
... -meter.do you know if ula/cpu etc from a +2a ... use a [I]Ferranti [/I]ULA. But the Z80 CPU can ... routine.
[I][B]Mark[/B][/I]Spectrum 128 malfunctioning with DIVMMCI recently got myself a spectrum 128 (toastrack) and a DIVMMC card so I could load games from it. It all works fine until it has warmed up and then t…
... normally dissipated by the ULA.
[I][B]Mark[/B][/I]Spectrum 128 malfunctioning with DIVMMCI recently got myself a spectrum 128 (toastrack) and a DIVMMC card so I could load games from it. It all works fine until it has warmed up and then t…
... dissipated by the ULA.
[I][B]Mark[/B][/I][/QUOTE ... the CSYNC signal of the ULA, heating the ULA up.Spectrum+ keyboard issueHi I have a spectrum+ (issue 4s board) where the 1-5 keys do not work. I have replaced the membrane and checked for continuity. I have also tested …
... , the input buffer in the ULA (which is addressed using A0 ... ideas...
[I][B]Mark[/B][/I]48K: Half of copyright message in the middle of the screen?!Issue two. Has 74LS08 over the Z80, but the ULA is 5C112E-3 (I think this should be a 5C102E??? - I have one, but I'm not sure if it is working, at l…
... here[/URL]
[I][B]Mark[/B][/I][/QUOTE]
Well ... was that the longer the ULA ran (which makes it very ... . I sort of cooled the ULA, which seemed to help.
Spectrum 128 malfunctioning with DIVMMCI recently got myself a spectrum 128 (toastrack) and a DIVMMC card so I could load games from it. It all works fine until it has warmed up and then t…
... voltage regulator followed by the ULA. Other chips such as the ... , use a heatsink on the ULA. Most of the chip as ... it.
[I][B]Mark[/B][/I]Dot crawl?Hi, As I'm rather new to the hardware of the spectrum, just to confirm: is this video showing "Dot crawl" ? [url]https://www.youtube.com/watch?v=_U…
... the video signal from the ULA to the SPECTRA, the SPECTRA ... slight timing variations in the ULA.
It is also ... ] help.
[I][B]Mark[/B][/I]VERY loud beeper!!I recently replaced a dead beeper with another from an old set of headphones, only this is MUCH louder! Is there a way of bringing the volume down a …
... /> TR7 is driven by the ULA via a 1N4148 diode, but ... , I will make some assumptions: ULA output pin logic high output ... the bleeper output from the ULA is left switched on. Speakers ... ) component ;-).
[I][B]Mark[/B][/I]VERY loud beeper!!I recently replaced a dead beeper with another from an old set of headphones, only this is MUCH louder! Is there a way of bringing the volume down a …
Hi Mark
You must correct ... is driven directly from the ULA at roughly 2V-PP according ...Diagnostic Board (Winston designed) PCB'sHi everyone, I had these made earlier in the year, built mine then promptly mislaid the others until now :) and I'd like to offer these to the commu…
... an indication that the CPU/ULA and address/data buses are ... any of these, then as Mark says you'll need to ...48k Spectrum ULA issue?Hi All, Have a couple of Spectrums Plus' with their orignal ULAs showing the failure as in screen 2 on the left. [URL="http://hardware.speccy.org/i…
Or either there is a data or address line (that connects to the ULA) which is shorted to either the +5V line or to 0V...
[B][I]Mark[/I][/B]Show some love for the Magnum Light GunI remember the reviews were mixed, but in hindsight I suspect the negativity was a result of the quality of some of those initial six games. I recal…
... out at what position the ULA was in building up the ... gun...
[I][B]Mark[/B][/I]48K rgb output? Also, OTLA.A couple of weeks ago I scored 2 48K Spectrums on eBay for ?27 with 1 PSU, 1 TV cable and about 10 tapes....score or what!!!! One turned out to be a…
The ULA in 16k and 48k Spectrums generates colour difference and luminance signals only. There are no RGB video signals in a 16k or 48k Spectrum.
[I][B]Mark[/B][/I]ZX Spectrum Clock Signal Restorer Circuit[SIZE=5][U][B]ZX Spectrum Clock Signal Restorer Circuit[/B][/U][/SIZE] The circuit below is an experimental circuit. It has only been "tested" using…
... approximation of what a distorted ULA clock output may be like ... critical.
[I][B]Mark[/B][/I]48k issue 2I have an issue 2 spectrum 48k and wanted to know if i wanted to change the z80 is ther any fix so i dont have that 1 component hugging the z80 [img…
... fix a problem with the ULA. On top of the Z80 ... about Sinclair Spectrum ULA's...
[B][I]Mark[/I][/B ...New Spectrum User - Inveterate UpgraderI've been asking a few questions about my Speccy, which is the first I've owned despite my advancingh years. I was a C64 kid, but please don't hold …
... the colour crystal and the ULA clocks not being locked to ... :lol:)
[I][B]Mark[/B][/I]Fixing my old ZX Spectrum 48K issue 4AHi Guys, I trying to fix my old Spectrum 48K. Looks like my dad used a wrong power supply as the ULA had a bit missing and so did the 7805. So I rep…
... read about:
> Some ULA chips in Interface 1's ... :p
[I][B]Mark[/B][/I]Crowdfunding ULAs?Hi everybody, I've found someone who's willing and able to make another production run of the Plessey ULA6C001E-7. We're not talking small amounts …
... run if that means each ULA is a silly high price ... done enough to recreate the ULA chips?
Oh and ... owners.
[B][I]Mark[/I][/B]Issue 3B no soundI just noticed that there's no sound in the Issue 3B Speccy that I've been fixing. Is it more likely that the speaker is bust or is it TR7 and D9? …
... , so I take that the ULA is good, right?[/QUOTE]
It certainty sounds like the ULA is okay :-)
Most ... speaker.
[I][B]Mark[/B][/I]Bypassing bits of faulty ULAs: the LOAD!Hi everybody, Recently I had a sick Spectrum sent to me. The symptoms were that the machine would run fine, except that it wouldn't load. The border…
... of your ULA by-pass surgery ;-)
[I][B]Mark[/B ...Issue 3B no soundI just noticed that there's no sound in the Issue 3B Speccy that I've been fixing. Is it more likely that the speaker is bust or is it TR7 and D9? …
... ]It certainty sounds like the ULA is okay :-)
Most ... speaker.
[I][B]Mark[/B][/I][/QUOTE]
ZX Spectrum 48K AV IssueOK so I dugout my old 48K Speccy today and decided to AV mod it. I did the mod (pretty easy) but the picture I am getting is this. [url=http://posti…
... is normal for both the ULA and 7805 to run hot ... now.
[B][I]Mark[/I][/B]
