-
SRAM replacement for lower 16KSome time ago I wondered if it were possible to replace the lower 16K RAM of a 16K/48K Spectrum with a single SRAM chip. You know, those pesky 4116 D…
... were possible to replace the lower 16K RAM of a 16K/48K ... -
ZX-81 Ram Pack problemHi! I know this is a ZX Spectrum forum, but I am hoping someone here might be able to help me out... I have posted this to c.s.s. but noone was able…
... original
Sinclair ZX 16k ram pack issue 3 .
lower with POKE 16389,n ... lt; 77 (76 and lower) and then do NEW then ... free (RAMTOP lower than ROM + 3.5k of RAM) then ... a posibility of faulty RAM somewhere on the lower
addresses ? ... -
How the spectrum generates the video from ramHi everyon, I know that most people here allready know this but i think i found out how the spectrum acctually dispalys stuff and why the LD x, (HL)…
... the first K of ram to video memory and ... cant also read the lower addresses at the same ...
The spectrum has its lower 16K separated from the higher ... is accessing the higher order ram (> 16K) the ULA ... data. Thing is the lower chip only needs to be ... -
zx81: is there a 16kb ram limit for basic?first of all, sorry to all about posting a question about zx81 in a forum mostly about zx-spectrum - i didn't want to offtopic questions here anyway,…
... time were only predicting 16kb ram extension, and this may the ... kind of zx81 alternative rom replacement supports whole 32kb, 48kb or ... -
4116 Ram chip replacements?Hello. I am in the work of gathering replacement parts for my speccy 48k. And I would like to know what chips is good replacement for the 4116 ram ch…
... in the work of gathering replacement parts for my speccy 48k ... what chips is good replacement for the 4116 ram chips, and where ... -
Lower Memory - Why Multiple Voltages?Having spent much of the weekend working on getting my old Spectrum working, my Dad (who is visiting) and I were chatting about the schematic. Given…
... />
Given that the upper RAM in a Spectrum is of ... the 4116 in the lower portion of RAM?
Surely it ... -
Replacement Spectrum +3 RAM ChipsHi all Bought a +3 last week with a RAM issue, so I have removed the old chips, added sockets and now just need a full set of chips to get her back…
... +3 last week with a RAM issue, so I have removed ... -
Spectrum +2 (grey) RAM issueHi, I?ve got a ZX Spectrum +2 (grey) with what I think is a RAM issue. I used to be able to load games very reliably by playing converted TAPs and …
... what I think is a RAM issue.
I ... that device is a 128K RAM test firmware.
... url], page 4) means that RAM page 5 has an issue ... think this is a suitable replacement: [url]http://www.mutant- ... the PCB is for which RAM page?
I ... -
Memory and Replacement ULA modules.Thought you might like to see my future proofed 48k version 6A with some upgrades fitted. Has had the following... Recap. Traco Power TSR 1-2450 p…
... 1-2450 power regulator.
Lower and upper memory modules from ... /
Nebula Spectrum ULA Chip replacement module from... http://www.retroleum ... -articles/nebula-spectrum-ula-chip-replacement-module/
Runs perfect, a ... -
MK14 keyboard replacementI'm the proud owner of a Science of Cambridge MK14! It seems fully functional, but the keyboard is a disaster - some keys don't seem to work at all, …
... checked through Google for any replacement keyboard, but it seems there ... to search for...
RAM I/O chip was not ... -
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 ... or 512x192 ) to occupy the lower 48K of memory and leave ... -
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 …
... d replaced _all_ the lower 16K RAM chips in my ... 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 …
... replaced _all_ the lower 16K RAM chips in my ... that writes to screen RAM every bit pattern, 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.
... -
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 ZX 48) are ... chips and put sockets - then replacement is peace of cake. -
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 ... carries power to the RAM chips). Replace the transistors ... , it's not RAM causing the problem and ... to supply the lower 16K of RAM with three voltages, ... how can i get replacement ROMs, original or flashed ... -
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 the ... bus being presented to the lower 16K and hence the snow ... ULA DOES NOT refresh the lower 16K !!!! Mad I know! Issue ... pulses....... So will my ULA replacement ;-) )
Watch out for ... -
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…
... - 1 Ghz Crucial CL2 PC133 RAM
- ATI Radeon 8500 ... .
PC133 RAM is a technology called SDRAM ... the latest boards use DDR3 RAM.
In ... Even if you buy a replacement second-hand, any ATI ... , which runs at a lower voltage. Your motherboard is ... -
Announcing: The +2A/+3 FLASH ROM adapter boardAs I've mentioned in a couple of other threads, this project is coming along quite well now, so I thought I'd post some details up here. I've built …
... +2a/+3 System Rom Flash Replacement Board Project.[/B]
specification ... selection of the upper and lower 64k banks of the FLASHrom ... connection to the spectrum's ram write line (connected to the ... a flying lead to a ram IC) allowing the FLASH rom ... -
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 equivalent ... on this forum which lists replacement types for the transistors). ... a quick, temporary replacement for that lower 16K in any easy ... makes diagnosis of if/which RAM chips are gone, difficult.< ... -
48k Out of memoryIv just had a 48k Speccy arrive today. The keyboard wasnt working right so I changed that. Now when I tried to load Cyclone it started to load ok fo…
... of RAM is more straight forward than the lower ... 16K.
You can buy off the shelf replacement RAM ... but you have to first work out what type of RAM ... upper 32K of RAM. Each RAM chip holds one ... two of the eight RAM chips require replacing ... -
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 …
... myself for the lower (16K memory). The lower 16K of RAM is problematic ... replace the DRAM with static RAM as you're not dealing ... with the ULA. The upper RAM connects directly to the Z80 ... [/I] useful.
Nb. Replacement 4116's aren't too ... -
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 …
[QUOTE=Robin;505619]this SRAM replacement, can it be done to ... ; there) as replacement for Spectrum DRAMs? Either for lower or upper RAM? :-? Or ... , you could replace the lower (or upper) RAM with just 2 DRAMs ... -
Requesting a little help to identify the purpose of this 'add-on' to my Issue 2Hi everyone First of all it's my first post here so please go easy on me! I'm grateful to be accepted into your fine little club :smile: I probabl…
... ](...)
Where can I source replacement TMS4532-20NL4 chips if it ... out to be bad upper ram?[/QUOTE]
From another ... *1 chip inside - with the lower or upper half in working ... -
RFC: Hardware Documentation ProjectI've noticed quite a few threads recently about missing schematics and suchlike. I've also been thinking about the low quality of some of the schemat…
... mode to help finding a RAM failure in non-contended area ... the computer, as if all RAM were damaged:
[url] ... memory to help diagnosing intermitent RAM failures:
[url]http:// ... url]
SIMM replacement for lower memory:
[url]http://www ... -
Diagnosing a strange software fault in a 48kHi, A friend gave me a 48k, which I am very keen to restore. The spectrum 48k was my first computer over 20 years ago and I owe my ability to code t…
... /RAS signals for the upper RAM and so the ROM code ... to use only the lower 16K of RAM. The output of the ... , where do I get a replacement IC23?
Seems that ... -
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 ... supply / memory chip related (mostly RAM, lower 16K in particular). -
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…
Although non-contended RAM (4532 chips) seem to be ... some time ago as a replacement for 4116 too, but with ... .php/simm-adapter-for-replacing-lower-memory/13-making-it-pretty ... -
Issue 3 board with strange piggy-back boardIn case you are interested. I?ve never seen something like this before. I have an Issue 3 board here. When I opened the case and found a strange pig…
... they should, since the lower 16k are not modified in ... lines going from the replacement IC25 and IC26 of ... link when they installed the RAM sockets. The fact that ... linked to one of the RAM address lines.
RAM chip fault), to take ... -
I know it's part ZX81 but what's the rest of it?You can see the ZX81 motherboard in the corner but I have no idea what the rest does, it powers up but I haven't managed to get the screen to tune in…
... />
- A ZX81 (obviously)
- Replacement keyboard
- In-built power ... is a DK'Tronics 16 RAM expansion.
- Tucked under ... socket and diving under the RAM board.
- Below it ... of ribbon cables (upper and lower side) link all the boards ...
