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The Complete List Of The Causes Of Lower Ram Failure?Well the aim is to get a comprehensive list.I ask this because I know very little about it . I know that failure of "power supply" related capacitors…
Well the aim is to get a comprehensive list.I ask this because I know very little about it . I know that failure of "power supply" related capacitors can do this . But I suspect there are loads of other ways to damage lower RAM ICs? Any ideas? -
upper ram tacks / TR4 socket...[url="https://photos.app.goo.gl/MkqzRCuNCV3EPr9E7"]https://photos.app.goo.gl/MkqzRCuNCV3EPr9E7[/url] you can only replace that pesky TR4 so many t…
... would just fry the lower ram again .. this is one board ... like somebody attacked the upper ram with a black and decker ... sugestions for replacing the upper ram tracks ? -
zx spectrum display corruption .. with lower ram module installed[img]https://photos.app.goo.gl/Gu6rjC5v21sZxwTX9[/img] [img]https://photos.app.goo.gl/FznVw8SkbbhWn5mh7[/img] another specie question : i have …
... video corruption, it has lower ram module fitted.. can get it ... it shows lower ram as good and upper ram not detected although ... start digging at the upper ram, or the 4 logic chips ... that drive the upper ram.. i am presuming that one ... -
Paging for 64Kb of Video Ram??? What is the best way to page this?Hi all, I'm just putting together a concept card for a "Loki" style of video card, which supports shadow ( so it fits a normal Speccy ) and also t…
... single 48K video page with RAM relocated to the ROM space ... -
Using a thermal camera to fix speccy's.Hi All, Thought I'd share another repair... Got a board that collapsed the bench supply straight away ( I run a bench supply and give it just enou…
... right is the 16 K ram chips. The ULA can be ... 12v generating circuit... Needs a replacement for a ZTX650... So I ... , and shows signs of previous replacement. Remove it, and replace with ... -
Built a ZX Spectrum that works, but can't get the upper RAM to work?Like the title says I finished my Spectrum 3B board, and it boots, but it doesn't see the upper 32k of RAM. When it boots, the lower 16k works f…
... see the upper 32k of RAM.
When it boots ... programs and even run a RAM diagnostic. Basically, tells me that ... all the associated logic, and RAM chips, with no effect. I ... direct connections between the upper RAM and associated logic, and I ... -
Max RAM for ZX Spectrum gamesHow much RAM can be used for single level/whole game? On tape writing.
How much RAM can be used for single level/whole game?
On tape writing. -
Crasched Spectrum+ 128, HELP!Hi! I recantly bought a Sinclair Spectrum+ 128 on a seconhand store. It shows random colour squares spread over the screen, mostly the upper part a…
... /> I'm now desoldering all ram's and will replace them ... out that some of the replacement rams is faulty. Found 16 ... -
ZX in FPGA...Hmm..seems nobody is interested in a replacement PCB with FPGA...well..heading towards next FPGA projects then...C64 and others (o; [ This Messag…
if it's an "replacement" PCB then i think you ... PIC-based PS2 interface (With RAM chip that emulates the kbd ... -
AmericaI've been wondering, was the Spectrum released in America? Was it popular? Are there Spectrum games that were made in America? There must be a few A…
... contains 16K rom and 48K ram as in the Spectrum, the ... . Each 64K piece could be RAM, ROM or a smart peripheral ... in sockets presumably for future replacement by the user. The ROMs ... didn't have the 128k RAM. I'm not sure why ... -
SpectaculatorWill there be an update for this fantastic emulator soon? It's been quite a while since the last one :)
... plugged in, it will promptly ram the heads of unit 0 ... says it's a direct replacement for a 5.25" drive ... -
Want a Speccy Repaired?Maybe it's time to put my 'skills' to use.... Now that I've sourced some of the nastier transistors, I've fixed about 6 rubber keyed Speccys in the …
... _all_ the lower 16K RAM chips in my dead ... program that writes to screen RAM every bit pattern, and ... and copies it to screen RAM, hence testing write and ... that one of my RAM chips was getting interfered ... of the upper RAM chips! A quick replacement later and yay ... -
Want a Speccy Repaired?Maybe it's time to put my 'skills' to use.... Now that I've sourced some of the nastier transistors, I've fixed about 6 rubber keyed Speccys in the …
... doesn't have any dead RAM in the top 32K. All ... a 48K Spectrum has bad RAM, though, it'll think it ... case you'll need a replacement ULA.
Hopefully that ... -
Want a Speccy Repaired?Maybe it's time to put my 'skills' to use.... Now that I've sourced some of the nastier transistors, I've fixed about 6 rubber keyed Speccys in the …
... that writes to screen RAM every bit pattern, and ... copies it to screen RAM, hence testing write and ... the upper RAM chips! A quick replacement later and ... now: I have suspected ram fault (coloured flashing blocks). ... must be something wrong with ram.
... -
Want a Speccy Repaired?Maybe it's time to put my 'skills' to use.... Now that I've sourced some of the nastier transistors, I've fixed about 6 rubber keyed Speccys in the …
... 't look like just one ram chip is faulty, but like ... something else. What are good replacement transistors (can't get those ... -
OT: Graphic Card problemAhem. It's me again with a computer problem! Last time I posted with a problem I was pleasantly suprised with some insightful answers that helped fix…
... card bios or graphics card RAM up the swannee - see ... on board RAM?
If shared RAM, try a ... likes to occupy "high RAM" itself. Not that it ... out itself, using system RAM, so you shhould check ... RAM.
I think you're looking at a replacement ... -
Atari STSaw one recently at a used scrap dealer, but didnt buy it seeing as it dosent have my particular interrest. I could probably bargain for it for only …
... accessible right away, unlike the RAM chips which require the removal ... modified to work as a replacement for the internal discdrive in ... -
256 color spectrumhi i start to make a project. a 256color spectrum like the spec256 emulator. capable to run 256 color games and the original ones from a cdrom,a flop…
... powerful while using the same RAM area(s) as the normal ... already developed a pretty powerful replacement ULA so it's certainly ... -
RAM chips are 4164s and 4564s interchangeableI paid for some 4164s online, for upgrading my Spectrum 16K to 48K, and I've been given 4564s. I've tried these along with the correct logic ICs and …
... produces it more.
Ask replacement...[/QUOTE]
Quite ... swopping the position of the RAM ICs. That is to ... , take out all the RAM chips, and put them ... you may still have bad RAM. The ROM routine to ... t test every bit of RAM, just every address. If ... -
Where to get Spectrum RAMSigh. Even obsolete nixie tubes seem to be easier to get hold of than Spectrum RAM. I've tried the usual suspects (eBay and google searches), but not…
4116 RAM chips (for lower 16K of ... chips and put sockets - then replacement is peace of cake. -
Spectrum RAM Paks...This jogged my memory (excuse the pun!!) : [url]http://cgi.ebay.co.uk/CURRAH-32K-RAM-PACK-BOXED-SINCLAIR-ZX-SPECTRUM_W0QQitemZ150057889352QQihZ005QQ…
... put one of these 32K Ram packs on a 48K Spectrum ...
when i got a replacement 48k I tried the rampack ... -
Dead Spectrum diagnosis and desolderingI have two dead Spectrums - one I'm pretty sure is caused by bad memory, and the other - well, perhaps a bad ROM, perhaps a bad CPU (it gets halfway …
... show up, true - but bad RAM, dodgy Z80, dodgy ROM etc ... 48K machines that just needed replacement capacitors to cure the bad ... -
Component Equivalents/substitutionsA while ago, I mentioned to somebody in a thread that we should have a list of component equivalents and substitutions so that it's easier to fix our…
... work as a drop-in replacement for 74LSxxx. Not tried it ... replaced with one 32KB static RAM chip and 74LS00.
RAM.
Last but not ... -
Component Equivalents/substitutionsA while ago, I mentioned to somebody in a thread that we should have a list of component equivalents and substitutions so that it's easier to fix our…
... .[/QUOTE]
It is replacement in meaning that is functionally ... my site about 2 mentioned RAM rep/mod... -
Best replacement for ZTX650?What is the best replacement transistor for the obsolete ZTX650? I've read that TIP31 will do the trick. Is there a decent equivalent from the BC or …
... .
In addition to the RAM, also check:
TR5 (check ... .
I hope its the RAM because if its not it ... is rather unusual for bad RAM to cause such a symptom ... on a 48k as a replacement? it looks a bit weird ... -
a dumb question?Well, I have been confused with all these interfaces so I have the following question which will make things clear for me... ;) Is there a "device" …
... generally require additional software or replacement ROMs for your ZX, tho ... interface's own RAM.
Since the RAM is battery-backed ... -
a dumb question?Well, I have been confused with all these interfaces so I have the following question which will make things clear for me... ;) Is there a "device" …
[QUOTE=piters;167189]Replacement ROM may be on interface, ... well with only (battery-backed) RAM. It only takes a couple ... -
Best replacement for ZTX650?What is the best replacement transistor for the obsolete ZTX650? I've read that TIP31 will do the trick. Is there a decent equivalent from the BC or …
... fault. First, remove all RAM chips from their sockets ... that carries power to the RAM chips). Replace the transistors ... blows, it's not RAM causing the problem and ... the lower 16K of RAM with three voltages, it ... how can i get replacement ROMs, original or flashed ... -
I/O contention model questionHi everyone, Sorry for my poor english. Together with a friend we are working on ZX Spectrum 48k implemented in FPGA. We have found bug in the Spect…
... - why DDR, when 32kbyte static ram ICs are cheap, trivial to ... (and thefore the entire upper RAM can be done with a ... used as a slot in replacement for the AY.[/QUOTE]
