-
Issue 4S differencesI decided to buy an Issue 4S PCB after reading much about them on here. It was originally in a plus case which didn't come in the sale. I've been run…
... 2SC945 transistors as general NPN signal transistors instead of ZTX313. This ... read this might be because M1 isn't implemented properly on ... -
Issue 4S bad M1Never ever seen a 4S with a bad M1 line before today [url=http://postimg.org/image/o2yrigdb1/][img]http://s14.postimg.org/o2yrigdb1/IMG_1291.jpg[/img…
Never ever seen a 4S with a bad M1 line before today
[url=http://postimg.org/image/o2yrigdb1/][img]http://s14.postimg.org/o2yrigdb1/IMG_1291.jpg[/img][/url]
But it is! -
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…
... ][U][B]ZX Spectrum Clock Signal Restorer Circuit[/B][/U][/SIZE ... -
MISSING M1 LINE ON +48????I was posting questions about my DIVMMC enjoy not working on one of my +48`s and have now got round to testing if its cpu related.Trouble is the one …
... a little about the faulty m1 line and i think 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…
... stay white, as though no signal was being picked up. The ... was starting to get a signal and then aborting (you know ... if it gets a bad signal - a bit of red/cyan ... start again. So the signal is too weak.
Not giving ... -
My attempt to restore the CPU clock signalI know Winston has already got this, but I can't see any thread with details about it. Only wanted to share my (still early) results. I'm not taking…
... reshaping the ugly shaped clock signal available from the rear bus ... give me a ininterrupted clock signal, filling the gaps where ... />
From this restored clock signal, it's easier to syntesize ... respect to the clock input signal.
[code]module ... -
RGB video issue on +2 and +3. Signal high?I have a couple of +3's and a new +2a that arrived today. When I plugged in the +2a using my RGB lead from Retro Computer Shack I was reminded of a n…
... the ChinnyVision videos dislikes the signal and keeps cutting out (I ... -
ZX Spectrum+ DivMMC EnJOY! Grundig 16" LCD TV and books.The Spectrum is in very good condition. Composite video mod. New mambrane (bought in November 2014 from rwap_software [url]http://www.sellmyretro.co…
... . Suspect existing CPU has faulty M1 output.
- Replaced all ... present.
- Confirmed CPU /M1 output not present.
- Fitted ... produced.
- Confirmed CPU /M1 output is functioning.
- Re ... 2,2.
- No signal at TR7 base. Suggests D9 ... -
No RF signal from modulatorGot a bit of a strange fault. I've got an Issue 2 spectrum which the TV doesn't lock onto. The TV locks to other Speccy outputs.<div><br></div><div>I…
... ) and I have a decent signal to the modulator (I get ... -
Bizarre ZX Spectrum faults (also possibly relevant to Spectranet compatibility problems).I'm attempting to repair an issue 4A 48K ZX Spectrum and am encountering some very strange problems. For my own records I've given this computer the …
... Z80 had a non-functioning /M1 output (this is very common ... CMOS Z80 and confirmed its /M1 output works correctly. ZX285 would ... , but one with a working /M1 output. The Spectranet interface now ... occurs in a proper video signal. For example, I explicitly looked ... -
Faulty M1 or no?Hi all, OK, so I've got an issue 4B which was pretty much untouched and appears to work fine (starts up OK, loads games, 23732 and 23733 both retu…
... I thought, "aha! a dodgy M1 line", so I removed the ... -
How to amplify the TV out signalI have one of these handy USB sticks where you can input a composite signal, left audio and right audio, but it can also accept UHF/VHF signals (in o…
... you can input a composite signal, left audio and right audio ... ), to boost the UHF/.VHF signal that comes out of the ... -
Issue with TV signal + Inductor Coil (16K Issue 2 Speccy)Hello guys, I just got a 16K Issue 2 Speccy from eBay. It was sold as not working so I knew there would be some work needed before it's working ag…
... noticed an issue with TV signal which normally was near perfect ... showing the issue with TV signal and another one with the ... possibly be behind the TV signal breakage?
Thanks ... advance.
1) TV Signal - https://youtu.be/pQz6yP0PuIA
Oric Atmos HelpMaybe a bit of a long shot but there are enough skilled people here, so hopefully I can get some thoughts please. OK I have an Oric Atmos here, it…
... to the modulator is too weak (tis quite well documented afaik ... . I did try without any signal on the TV.
signal. Manual adjustment did not improve ...Games with proximity warning signal?Hi all. Are there games on ZXS with proximity sound signal? I mean the style like in the Aliens movie. The marines crept through the complex and as t…
... on ZXS with proximity sound signal? I mean the style like ...Of course, when the M1 line of the Z80 CPU is failing, the Z80 CPU must be replaced![quote]Of course, when the M1 line of the Z80 CPU is failing, the Z80 CPU must be replaced![/quote] Err, why? If you are trying to use an interfa…
[quote]Of course, when the M1 line of the Z80 CPU ... Z80 MPU with a working /M1 line, yes of course.
M1 line. So it’s irrelevant ...Mysterious ZX_Spectrum network mysteryOK. You win... Whoever you are. I'll bite.. For about a year plus now, whenever connecting to my home wifi network, I have occassionally been seeing…
... ZXSpectrum_2GEXT' on the list of weak nearby networks. Perfectly sensible it ... WiFi for an honest signal test. The signal doesn't seem ... free 'network finder' or 'signal strength' apps. But they appear ... utter junk. Plus the signal strength appears to fluctuate; ...zx spectrum +2A / +2B no clock signal or video display / gate array dead ?scratching my head with this sick specie .. it is a issue 4 .. i was hunting for R45 that goes between the clock signal of cpu and gate array,, but i…
... that goes between the clock signal of cpu and gate array ...blew up my 128i did it - damn. i accidentally reverted the polarity of the power power supply, so ended up with a blown 5v stabilizer, which i replaced, but there …
... 't work and signal to modulator is too weak. But worse thing ... . It means, that composite video signal is NOT generated at all ... . Modulator has no signal on input, so it cannot ...Interface 1Hi, Just got myself an Interface 1 only to find it does not work. That is to say that I can't use any of the extended commands on it,e.g. CAT 1, LOA…
I think the signal M1 from CPU is not here anymore, without any interface you will not see any fault, so replace the Z80 and anything will be fine.Parasol Stars for Spectrum Having played a lot of Bubble Booble and Rainbow Islands on Spectrum, and later on also Rainbow Islands and Parasol Stars on Amiga, I feel like it w…
... isp they said therres a weak signal , someone should come down in ...Microdrive Mayhem!I'm wandering if anyone can help me. I recently acquired an Interface 1 plus a couple of Microdrives. But I can't get them to work properly. The Int…
... Spectrum, it doesn't work (signal too weak?).
Anyway, I ...Games that wouldnt loadI had a few of these, and even after taking them bck some still didnt load first time :( anybody else have/had games like this The pain in the asses…
... ...
- Showjumping was a pretty weak signal.
- Xadom never worked *ever ...InterruptsA small piece intended for the FAQ. Comments, corrections, additions welcome. Notably: * How long does the 48K ULA hold /INT low? * What happens i…
... is that the /INT signal must be taken low on ... reach 0x0038:
* M1: 7 tstates: acknowledge the interrupt ... interrupt routine:
* M1: 7 tstates: acknowledge interrupt and ... 19 cycles:
* M1: 6 tstates: acknowledge interrupt.
InterruptsA small piece intended for the FAQ. Comments, corrections, additions welcome. Notably: * How long does the 48K ULA hold /INT low? * What happens i…
... But that's referring to M1 of an interrupt acknowledge cycle ... with its usage of "M1". An M1 cycle is usually understood to ... cycle (called that because the signal /M1 goes low when an opcode ... interrupt acknowledge cycle when the signal /M1 happens to go low at ...Sparky eZX-BASIC Project in need of FPGA ExpertYou probably are not familiar with this project, but it is a computer system based on Zilog's new eZ80 chip and the OS is a superset of ZX BASIC. Ju…
... had just brought the WAIT signal outside the chip, then things ... /> There is no longer a M1 pin nor a WAIT pin ... inactive, as there's no M1 to tell you and there ...saving tzx in realspectrumwhen I save a tape in realspectrum as a .tap or .tzx, It wont read it, What am I doing wrong. Does the fast tape have to be turned off? and if so why…
... similar to a weak or over-strong tape signal. The signal seems to ...What's the maddest a Speccy game ever drove you????What's the maddest a game ever made you and what did you do about it?? I have plenty of memories of punching TV's, myself, sofa's etc. as, for exampl…
... game because the Speccy's signal was weak and my cassette recorder ...Sound mod for AY audio chipsHi again. This is a repost. I posted it in the misc forum a while back but it definitely should be in here. I was totally pissed off with the crap…
Yeah I've seen Cristians mod. Thats what gave me the idea for buily and amp/mixer (his one has a weak signal). His diagram is taken from what is used on a CPC464.
Where are you seeing pins 48 &52?
