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ISR's in lower ram, a.k.a. the snow effect - did any game or demo ever use this?Hi all I've been curious to see what the 'snow effect' looked like in real life for a while now so today I wrote a quick IM 2 ISR in lower ram to wi…
... quick IM 2 ISR in lower ram to witness it firsthand. Pretty ... -
16K/48K Lower RAM (4116) replacement.You may want to read [URL="http://www.worldofspectrum.org/forums/showthread.php?t=37957"]this thread[/URL] for background information on the quest t…
... SRAM based replacement for the lower RAM that works in all 16K ... the column address to the RAM and so there isn't ... levels that appear on the lower RAM address lines. In particular, in ... this is the ZX Spectrum Lower RAM Replacement Module, pictured below:
12V ripple with lower ram installedI repaired a speccy this week. Before doing anything I replaced all caps and measured the transistors in the power section. When doing this I found t…
... Then removed and socketed all lower ram. turned the speccy back ... the scope. Inserted a lower ram module and the speccy was ... Then removed the lower ram module and reinserted all original lower ram ic's ... wasn't there when the lower ram module was inserted.
...help with my original issue 3b from when i was a teen. possible lower ram fault.hello, well ive tried to fix my old speccy, but haven't made much progress. could you help me out with some diagnosis. the fault occurred about…
... /> is this more likely a lower memory fault? or is my ... certain before I order a lower ram set.zx.zigg.net lower RAM replacement module: Still shipping?Hi everyone I'm trying to resuscitate my 48k issue 6a, and I bought the lower RAM replacement module from zx.zigg.net. The paypal payment went thr…
... 6a, and I bought the lower RAM replacement module from zx.zigg ...Replacing lower RAM 4116 ZX Spectrum 48k - desoldering advice please?A long post, but interesting pictures perhaps. :) I'd like some advice: (also apologies I think I picked the wrong 'Hardware' category for this, plea…
... online seemed to indicate a lower RAM issue. It hadn't been ... solder was applied to the lower side and it had travelled ...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?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 …
... with video corruption, it has lower ram module fitted.. can get it ... and 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 ...Lower & upper ram IC's for an issue 3 please.Would any of you great folks have 1 spare lower ram, and 1 spare upper ram IC's you would be willing to sell. I'm fixing up a poorly Spectrum that is…
... have 1 spare lower ram, and 1 spare upper ram IC's you ...4116 ram chipsI need some ram chips to fix my 48k + issue3b, I have done the composite video mod and it works, now i just wanna play games on it but its stuck on r…
I need some ram chips to fix my 48k + ... been advised to replace the lower ram chips. I can't test ...Not worth reading really - unless you have some spare time(Mods if you want to move it please do it does have a sort of hardware theme and a couple of recommendations at the end :) About two years ago now I…
(Mods if you want to ... had died was the ULA/lower ram, so what would cleaning ... on the speccy, IF1 and RAM turbo do? So I ... did my best with the RAM turbo as I can' ... unplugged - no IF1 and no RAM turbo, swithed her on.... ... with the IF1 and the RAM turbo and all is ...Difficult to find upper RAM fault.I've recently repaired an issue 3B 48K Spectrum that had a tricky to diagnose upper RAM fault, so I thought I'd post a report of what I found here. …
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Next, the section RAM-READ begins examining and modifying ... code passed from testing lower RAM to upper RAM. Here is an ... is the last byte of lower RAM (32767) being (successfully) ... capture the RAM-FILL routine passing from lower RAM to upper RAM, but ...ZX Spectrum 48k Issue 2 Faulty Ram?Hi, I have a faulty ZX Spectrum Issue 2 motherboard. Looks in very tidy condition. Though I'm getting random columns of blocks and flashing cursors…
... have read would indicate a lower ram failure. I have lightly touched ... seem cool.
The ram fitted is 8322 4116 2N ...ZX Spectrum upper RAM module (4532/4164 replacement)Following the [URL="http://zx.zigg.net/LRR/"]lower RAM replacement module[/URL], there have been quite a lot of requests for something similar for th…
... http://zx.zigg.net/LRR/"]lower RAM replacement module[/URL], there ... http://zx.zigg.net/LRR/"]lower RAM replacement module page[/URL] ... the same as for the lower RAM device.
... circuit as the lower RAM replacement and emulates dynamic RAM.
Power consumption improvementsHi all, Having just received lower and upper RAM replacement modules from Zorn, I thought I'd perform some current draw measurements to see how much…
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Having just received lower and upper RAM replacement modules from Zorn ... the RAM:
Recom + Lower RAM module: 260mA
Recom + Both RAM modules ... : 210mA
So those three mods have more ...128K RAM tester as .TAP?I was sure that I've seen a RAM tester that can be loaded with e.g. DivIDE or DivMMC EnJOY! as .TAP. But I can't find it (been searching through the …
... that I've seen a RAM tester that can be loaded ... on 128K machines, and if lower RAM works fine, and there is ... a small error in upper RAM.
I have a ...What are the chances?Hi all, I've picked up an issue 3B, fairly clean board, no mods, wasn't starting correctly so I tried Brendan's diagnostic ROM and got this: [i…
... 3B, fairly clean board, no mods, wasn't starting correctly so ... .jpg[/img]
Total lower RAM failure? Before I start pulling ... all the RAM out, is it possible that ...Spectrum 48+ 4S - Upper RAM issue, and now a self-created problem!I recently picked up a known-flaky spectrum off eBay, to have a bit of fun fixing it and reliving youth. It was labelled as 'keyboard duff, shows…
... tape version of Balford's ram test diagnostics said the whole ... of upper RAM was faulty (check all ICs ... 've removed all the upper RAM ICs, replaced with sockets and ... screen.
Given the lower RAM used to be okay, and ...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…
... it 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 ?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…
... 32k of RAM.
When it boots, the lower 16k ... even run a RAM diagnostic. Basically, tells me that lower RAM is good ... , all upper RAM bad. But the ... direct connections between the upper RAM and associated logic, and ...damaged spectrum+ (blinking squares)Hi, Sorry for my poor english, but I couldn't find on family forums any remedy for my hardware problem with my first speccy in my life :) I've bought…
... ... and board too - no user mods or repairs from the looks ... ... I'd be doubting between lower RAM chip(s), Z80, or perhaps ... Spectrum I'd just unsolder lower RAM IC's + Z80 now, test ...Was the +3 a missed opportunity?I just wanted to gauge WOS opinion on this. Do people think that the +3 was a bit of disappointment that didn't really advance the hardware as much a…
... -soldering circuit board traces doing mods. Basically indestructible.
When you ... /12v supply fails and the lower ram burns out! :smile:Was the +3 a missed opportunity?I just wanted to gauge WOS opinion on this. Do people think that the +3 was a bit of disappointment that didn't really advance the hardware as much a…
... -soldering circuit board traces doing mods. Basically indestructible.
When you ... /12v supply fails and the lower ram burns out! :smile:[/QUOTE]
lower ram failiure in my speccy 48 ...Issue 3 board... How to resurrect?Dear Everyone, Now I have a working 48k Issue 3, a sort of working Speccy+ (still having problems with the keyboard, more of that in another post) a…
... my failures are with the lower RAM chips, and sometimes with the ... upper RAM chips. Occasionally I find a ... not fitted with the necessary mods.First time capacitor replacementHi, I have an Issue 2 board, that i wish to start with recapping as advised on here, as they look to be all original. (Same with V3 board, but going…
... of replacing the lower Ram with one of his mods vs buying new ...Spectrum 48k ProblemsHi all Got my 48k today but it's playing up abit... First time i turn it on it was like this: [IMG]http://s26.postimg.org/hlg9d3f3d/IMG_20140830_…
... 9 at one of the lower RAM IC's with the ground ... one or more of the lower RAM IC's have gone bad ... , although upper RAM faults could also cause this ... #volchk"]here[/URL].
Mods: any chance we could have ...The Spectrum Resuscitation ThreadKicking off this thread as a place where people who are fixing/restoring Spectrums (or indeed any other piece of related hardware) can show off their…
... ="http://zx.zigg.net/LRR/"]Lower Ram Replacement[/URL] (LRR) module from ... aspect of the Spectrum (4116 lower RAM) and result in a power ... 've done this and other mods, they're floating round in ...The Spectrum Resuscitation ThreadKicking off this thread as a place where people who are fixing/restoring Spectrums (or indeed any other piece of related hardware) can show off their…
... ="http://zx.zigg.net/LRR/"]Lower Ram Replacement[/URL] (LRR) module from ... aspect of the Spectrum (4116 lower RAM) and result in a power ... 've done this and other mods, they're floating round in ... do have a list of mods, I'd really appreciate it ...Spectrum stuff online "buying skills". Are real skills needed for low cost Speccy items? Firstly , there are some pretty fundamental requirements that are probably too basic to mention , like buying the right software at the right pri…
... ="harriusherbartio;941435"]What are the mods needed to get to the ... /filter capacitors to a few RAM ICs (possibly a few other ... need one; likely just the lower RAM ICs. Smaller capacitances installed in ...Another Spectrum is brought back to life.Hi Spec-chums. I have been having bit of busy afternoon with repairs today. I've brought back to life a Panasonic Super-VHS recorder, and more intere…
... a lot of repairs and mods done along with a bit ... white screen? I know sometimes ram chips can be faulty, or ... if the Spectrum has faulty ram IC's. The diagnostic rom ... fault with 1 or more lower ram IC's. But the other ...
