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4116 SRAM replacement (and ULA timings).As mentioned in another thread, I have spent quite a lot of time experimenting with different circuits and components for using a static RAM IC to re…
... RAM IC to replace the lower RAM 4116s in a Spectrum ... installed, CPU access to the lower RAM seems to work perfectly ... from a different, but related memory location when the incorrect pixels ... ULAs that may affect their memory access. I rather suspect there ... -
My Issue 2 spectrum"IT'S ALIVE!!!!!" - Dr Frankenstein I got my issue 2 spectrum up and running, colours and all. I borrowed socketed lower ram from my issue 3 that is…
... all. I borrowed socketed lower ram from my issue ... well as it did lower ram and cpu. They ... the sockets again, the memory modules work, seems old ... cpu (Nec 780008C), memory borrowed from my Issue ... memory sent to me by BVerstee, thank you again), and replacement ... -
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 have ... ://zx.zigg.net/LRR/"]lower RAM replacement module page[/URL] and ... the same as for the lower RAM device.
... the same circuit as the lower RAM replacement and emulates dynamic RAM ... -
Upper RAM replacement module issues with the DivideI got my new upper ram replacement module from Zorn yesterday and seem to be having some issues. When the machine is without the Divide it boots up …
... got my new upper ram replacement module from Zorn yesterday and ... boot, the ram passes the memory test i perform with the ... uses unusual timings that the replacement can't cope with.
Replacement 3D printable case on thingiverseI'd like to know people's thoughts on this: [url]http://www.thingiverse.com/thing:226892[/url] It claims to be a replacement case for the rubber ke…
... /> It claims to be a replacement case for the rubber key ... , so I'm going from memory here but:
1 ...Issue 6 repair with a twist...(Starting with a slight grump - the forum ate my first attempt at this so this'll probably end up being a bit terse :)) I got a Issue 6 48K machine …
... the diags were reporting both lower and upper RAM were healthy ... br />
Now suspecting a lower RAM issue, I entered and ... ).
One swift 4116 replacement later, and the machine was ... some lengths to ensure that memory is well exercised.
Spectrum +2a memoryHi all, Happy New Year. A quick question, I have a Spectrum +2a that I am seeing a very intermittent fault, once every 20 - 30 power ups. I plug…
... it seems to fail the lower 16K memory test.
Does ...TR4/TR5 replacementHi guys, I've got another Spectrum I'm working on now - an Issue 4S this time. When I originally got it, I powered it up and did the basic tests a…
... I've now got some replacement parts for that so it ... ]. Testing the voltages on the lower RAM IC's show they ... are still wrong on the lower RAM IC's, so I ...Upper memory not available in issue 2A friend send me his issue 2 Spectrum for diagnosis. It boots okay but for some reason won't load games over 16kB. He sent also a Smart Card with int…
... ROM, which failed the upper memory RAM test, suspecting IC25 and ... .
Both upper and lower memories have been upgraded prior ... high to enable the upper memory and under which conditions? Any ...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 ... chips, nine 16-dip sockets, replacement keyboard membrane. My plan is ... solder was applied to the lower side and it had travelled ...divIDE interface not workingA while ago I bought a divIDE interface for my two spectrums (one is a 48k rubber keyboard one, the other is a 48k Spectrum plus). Sadly I never actu…
... both upper and lower RAM with a new replacement boards, recapped the ... that were already on the memory card). Not to mention some ...Zx Spectrum Laptop (again)I've been reading all the old treads about a possible portable speccy. I even found the one about the Speccy Laptop. But it seems there's a lot of ne…
... /O pins for a ULA replacement - IIRC, all but four pins ... can also natively access external memory (in parallel, with a full ... low order bit of the lower half of the address bus ...Got my mac mini and I'm in loveI have had it for about 2 days now and it is the 2nd best piece of computer equipment i have had, it is quieter then my dvd HD recorder i have been s…
... a "desktop replacement" laptop.
For me extra memory, HD size ... is static information.
Memory - As much as possible. On ... to go over ?750. However memory is relatively cheap at the ... the graphics that kill the lower end macs for me.
I want to build a new, super spectrum ;-)only kidding Andrew :-) my brain's going at a mile a minute at the moment, so I thought I should put some of the ideas down in case one of them is w…
... project - not a ULA replacement, but for a CP2200 based ... the original 74LS TTL, and lower impedance outputs. Indeed, the ... small set of DRAM replacement daughterboards - one for lower RAM, one for ... perfectly good 4116 and 4532 memory.
[0] no, ...ULA RAS, CAS cycles, refresh and "snow effect"Hello everyone. I have a question, does anyone observed timings of RAS and CAS generated from ULA? I think there may be answer to where the "snow ef…
... Z80 wants to access the lower 16K ram. What happens during ... has given to the video memory.
Hope that helps ... ULA DOES NOT refresh the lower 16K !!!! Mad I know! Issue ... pulses....... So will my ULA replacement ;-) )
Watch out for ...4116 DRAM for 48KSomeone told me I got faulty RAM in my broken 48K. They should be 150ns, right? What would be a good place to buy them from?
... had the same problem (lower 16K memory bad) and tried replacing ... reads / writes to the lower RAM. Snow gone, normal ... used (eg. as video memory for a TMS9918 chip).
lower)
* Replace +5 ... PCB as plug-in replacementupgrades what you looking for?i start working for upgrades for ZX, but i'm Atari specialist and i don't know exactly what you need for ZX. On the moment i have DIVIDE in stock, an…
... one ;)
Recently replaced the lower RAM on a Speccy 48K ... into a generic 4116 DRAM replacement. Think: a ready-made, ... card to Spectrum's main memory. Oh - and media fully ... />
2) A full Spectrum replacement (48K or 128K compatible). Think ...building a PCIv'e decided to get my old PC and try and get the thing working again. not really sure what went wrong with it, and instead of buying a new one i pre…
... 't put one type of memory in a socket designed for ... . Even if you buy a replacement second-hand, any ATI Radeon ... interface, which runs at a lower voltage. Your motherboard is old ...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…
... circuitry that serves video + lower 16K RAM chips (4116 or ... on this forum which lists replacement types for the transistors). ... insert a quick, temporary replacement for that lower 16K in any easy ... manner, while you need that memory ...repaired a 48K, yay :)I just managed to repair one 48K. After socketing all eight lower RAM chips (hard work!) and replacing few of them, it showed the familiar "Sinclair …
... this myself for the lower (16K memory). The lower 16K of RAM is ... , for the upper (32-64K) memory area, it's quite easy ... [/I] useful.
Nb. Replacement 4116's aren't too ...Repairing a faulty 48K issue 2.I am investigating one of a pair of non-working issue 2 48K Spectrums that have been sitting in a cupboard untouched for quite a few years. I haven…
... the top half of the lower 16K of RAM.
... blame.
When the memory corruption occurs within the display ... the very top of the lower 3rd of the display ... bus/control signal for the lower RAM.
Are ... it should be an acceptable replacement.semi dead speccy 48k who can helpHi forum , i am busy recovering a 48 k speccy issue 3 board unit. With the help of a more experienced spectrum user from the uk , i managed to get…
... ? (add to your profile?). For replacement ULA's you could try ... I doubt you need a replacement ULA in this case. Most ... ), and power supply / memory chip related (mostly RAM, lower 16K in particular).lower ram "new" replacement board.[url]http://www.ebay.co.uk/itm/230994088030[/url] I'm sure others have seen it .. but is it "like for like" compared to the original. .with regard …
... ULA/CPU. So long as memory devices respond appropriately within the ... to detect an SRAM replacement for the lower RAM. It couldn't ... detect data corruption as the lower RAM is refreshed by the ...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…
... a keeper :)
Usual lower RAM defective stripes along with ... a full 48K of working memory.
The membrane, which ... together. Not to worry though, replacement on order and this machine ...48k Stops loading and resetsI've just fixed the problem I had with my Issue 2 Spectrum only showing 16k memory by replacing all of the upper ram. With that job done I've done a …
... this the one with the replacement chips being 4532's?
memory correct according to the type ... swapping ULA, ROM, CPU and lower RAM to see if that ... showing itself as having 48k memory.
Mart48K Upper memory issues?Having more issues with the 48K spectrum I just fixed that had the black screen in this thread [URL="http://www.worldofspectrum.org/forums/showthread…
... the standard Electrolytic capacitor replacement.
Now powers on ... the screen. Replaced faulty Lower Ram IC (IC8)
lower ram chips were not ... not all of the memory was seen. Also occasionally ... Tried to run the memory test that ZORN linked ...Video ZX Spectrum+ 48k<span>Good day ... is a bit of time that I try to fix my zx spectrum ... I replaced the ram 4116, all electrolytic capacitors ... but the monitor loo…
... ULA's ability to access memory.
It may be ... a replacement ULA will cure things, or the use of a lower ...48k not startingHi team, I have 2 48k's, one works (Issue 4s), one doesn't (Issue 4a). The non-working one appears to start, but not finish the RAM test. The pape…
... some pins of the lower and upper memory chips (some 0.5V ... the external ROM and a replacement ZTX450.
N ...Faulty Issue 1Hi all, thought I'd document my efforts in getting another speccy working. I've never done this before so please bear with me... I recently took a p…
... (/RAS, /CAS, /WE) on the lower RAM end. But I'm ... check though: (with that RAM replacement module inserted)
a) ULA ... Z80 memory reads, Z80 memory writes, or ULA reads from the lower RAM ...Testing 4116 type DRAMsHappy New year All! I'm managed to find some time to repair some more Spectrums :) woo hoo. I have a couple with busted lower RAM, Sooo, I appr…
... for errors in individual bits / memory locations.
So basically ... actually make a ram module replacement with ease?[/quote]
Perhaps ... 64K*4 DRAMs, or a lower RAM replacement module.
