World of Spectrum
  • Categories
  • Discussions
  • FAQ
  • Sign In
Home › Search
Title Search
@title beer Word 'beer' in title
User Search
  • @user admin Only posts by Admin
Text Search
  • @body beer Word 'beer' in the text
Phrase Search
"Hello World" Exact phrase match
Exclude Terms
  • car -red Search cars that are not red
"Or" Searches
  • honda | bmw 'honda' or 'bmw' results
Multi-Field
@(title,body) hello Both contain 'hello'
WildCard
  • hond* civ* Match all with an astrix
Combination
  • @title bmw @user admin
See more supported syntax examples
Search Again :: Adv Search 1000 results in 0.024s
<1234567…34>
  • 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. …

    ... section named RAM-FILL loops over all possible RAM addresses, from high ... passed from testing lower RAM to upper RAM. Here is an ... first read from the upper RAM location retrieved the decimal ... capture the RAM-FILL routine passing from lower RAM to upper RAM, but ...
    Zorn Zorn April 2012 Hardware
  • 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…

    ... and almost works only when certain keys are entered does start ... would just fry the lower ram again .. this is one board ... looks like somebody attacked the upper ram with a black and decker ... .. any sugestions for replacing the upper ram tracks ?
    mark8bit mark8bit September 2020 Hardware
  • 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…

    ... doesn't see the upper 32k of RAM.

    RAM is good, all upper RAM bad. But ... the associated logic, and RAM chips, with no effect ... direct connections between the upper RAM and associated logic, ... PEEKed at the 8 addresses above 23733 (from ...
    DistantStar001 DistantStar001 June 2022 Hardware
  • Alternative chips for upper RAM blockDoes anybody know of a way to use 4464 chips instead of 4164 for the upper RAM block in a 48K machine? If not 4464 then something a little more avai…

    Does anybody know of a way to use 4464 chips instead of 4164 for the upper RAM block in a 48K machine? If not 4464 then something a little more available than the 4164. Winston? Piters??

    TIA
    DEATH DEATH August 2007 Hardware
  • 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…

    ... for something similar for the upper 32K RAM in a Spectrum.
    upper RAM module instead or one of ... of trailing wires, so the upper RAM module uses almost the same ... as the lower RAM replacement and emulates dynamic RAM.

    ...
    Zorn Zorn July 2013 Sales
  • 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 …

    I got my new upper ram replacement module from Zorn ... . When I put the upper ram chips back in place, ... again.

    The upper ram are not on the "OKI ... that also has the upper ram module be so kind ... attempts DMA to the upper RAM and uses unusual timings ...
    gtsamour gtsamour September 2013 Hardware
  • Issue 2 Upper Ram, Loading & ResettingI have a 48k Issue 2 Speccy and for the life of me can't track down what the problem is with it. I initially thought that some of the uppe ram ic's w…

    ... some of the uppe ram ic's were faulty ... went on to desoldered the upper ram ic's, socketed the ... board and replaced the ram with known good chips. ... replaced all the upper ram with known good ram from another Issue ... cant now be the upper ram as I swapped and ...
    retrogamemart retrogamemart December 2014 Hardware
  • 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…

    ... diagnostics said the whole of upper RAM was faulty (check all ICs ... , I've removed all the upper RAM ICs, replaced with sockets and ... .

    Given the lower RAM used to be okay, and ...
    Paulcatchpole Paulcatchpole December 2016 Hardware
  • 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 ...
    Your Spec-chum Your Spec-chum September 2017 Wanted
  • Looking for some 48k RAM (upper 32k bank)Greetings, I was wondering where I could find some upper RAM for a 48k (issue 4A). It's the Texas Instruments TMS4532-20NL4 P8419 (or any compatib…

    Greetings,
    I was wondering where I could find some upper RAM for a 48k (issue 4A).
    It's the Texas Instruments TMS4532-20NL4 P8419 (or any compatible RAM).

    Thanks,
    Thomas
    thomas3120 thomas3120 February 2010 Hardware
  • The Disciple clone... doable?Hi. As a spectrum user in the 80's this was the dream interface all-in-one for me. I have a 48k+ and planning on get a 128K toast-rack later. Anyway…

    ... Disciples ROM and RAM banks have no fixed upper/lower position, as ... *and* RAM are both paged in upon execution at certain addresses (although it ... ROM at #0000 and the RAM at #2000 whenever the DISCiPLE ... . Writing to the port places RAM at #0000 and the ROM ...
    zub zub February 2013 Hardware
  • divIDE issuesI discovered a few issues with the divIDE hardware and FATware software that may be of interest to some people. 1. ROM paging If your Spectrum is a…

    ... Spectrum is able to page RAM over the BASIC ROM the ... is unaffected by divIDE but certain addresses will still cause it to ...
    chev chev October 2005 Development
  • Adventures in Programmable Logic Part 2So, now armed with an Xilinx Parallel III cable, an XC9536 CPLD, a breakout board with power, a JTAG pin header and a 44-pin PLCC socket, I could try…

    ... for the flash ROM, workspace RAM and W5100
    - contain the ... (i.e. trap execution at certain addresses to cause a page-in ...
    Winston Winston December 2007 Hardware
  • It's a trap!So I got a CPLD (not the eventual one I want to use for the ethernet project - rather, one I actually have here and now, an XC9536 in a PLCC44). And…

    ... instruction fetches at the following addresses

    - 0x0000 - only when ... , by fooling it into thinking upper RAM is being accessed. (This will ...
    Winston Winston December 2007 Hardware
  • Replacing Upper RAM in 48KHi Folks Well, my fun continues :) After sorting the display issues with this machine I found I couldn't load software meant for 48K machines. Havin…

    ... here it looks like an upper memory fault.

    Before ...
    spookt spookt July 2012 Hardware
  • POKEs on 128K "upper RAM"?I've been working lately with some 128k games, and I've got this question about RAM in games. I guess most games use RAM pages 5 and 2 to store the …

    ... 've got this question about RAM in games.

    I ... guess most games use RAM pages 5 and 2 to ... the main program, and other RAM pages are used to store ... that needs POKEs placed in RAM pages 1, 3, 4, 6 ...
    Zup Zup October 2013 Games
  • Interesting 48K failureI thought I'd recount a failure I've not seen mentioned before that I saw tonight while fixing a 48K issue 6 board. The background: The initial fail…

    ... :
    1. A fault in upper RAM causing incorrect instructions to get ... odd numbered I/O port addresses. This was never fixed inside ...
    Winston Winston December 2013 Hardware
  • Seriously weird Issue 2 issue... (RAM-related)Hi guys; I have been trying to fix up my Issue 2 and have run across a bizarre issue that I haven't seen elsewhere in the forums. Hopefully one of …

    ... .
    2. MEMCHK returned 32767, upper RAM fault. UPRAM85 returned 93, so ... "black screen and red bars" RAM test appears, after which the ...
    Trafferth Trafferth August 2014 Hardware
  • Upper Memory LinksI've got an 1982 Issue Two Spectrum 48k with an upper RAM fault. I've narrowed down the faulty IC and I'm in the process of removing the 8 IC's, sock…

    ... Two Spectrum 48k with an upper RAM fault. I've narrowed down ...
    retrogamemart retrogamemart September 2014 Hardware
  • 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 …

    ... />
    I suspected faulty upper RAM trashing the stack, and this ... were reporting both lower and upper RAM were healthy.

    ... />
    In this case certain pieces of data handled by ... then reinitialised, and the RAM being tested is compared against ...
    balford balford September 2014 Hardware
  • ZX81 internal RAM board?Just a quick question to Zorn (amongst others). What would the issues be with fitting one of Zorn's RAM boards into an unexpanded ZX81? Seems to me…

    ... fitting one of Zorn's RAM boards into an unexpanded ZX81 ... a lot of the official RAM pack's internal circuitry is ... fit one - preferably the 32K upper RAM board, 'cos I never had ...
    DEATH DEATH October 2014 Hardware
  • 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 ... only a small error in upper RAM.

    I have a ...
    bverstee bverstee January 2015 Hardware
  • Upper memory issueZX Spectrum 48K, issue 2, boots fine. Lower RAM OK. When tested with the new test ROM in the Diagboard, for all upper RAM tests "FAIL" is shown. I…

    ... 2, boots fine.
    Lower RAM OK.
    When tested with ... in the Diagboard, for all upper RAM tests "FAIL" is shown.
    RAM, are the voltages:
    4116 ...
    georgedb georgedb September 2016 Hardware
  • Spectrum 48k won't start any software but passes all RAM testsI have a rubber key 48k which will not start any software - it appears to work perfectly right up until the end of the tape and the program would sta…

    ... was a problem with the upper RAM however on running the soak ... minutes. I also performed the RAM test detailed here http://www ... longer or look for non-RAM related issues?
    britain4 britain4 October 2016 Hardware
  • 48K Issue 2 RAM issuesI have 48K issue 2 board (I've checked, the upper memory is present!). It's not very well. I've not attempted to diagnose one before, so please bear …

    ... board (I've checked, the upper memory is present!). It's ... issues are only in the upper RAM as it will actually boot ...
    kurbeco kurbeco August 2019 Hardware
  • 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 ... and it shows lower ram as good and upper ram not detected although ... i start digging at the upper ram, or the 4 logic chips ... that drive the upper ram.. i am presuming that one ...
    mark8bit mark8bit January 2021 Hardware
  • Method to read byte as binary string rather than dec?Hi all Am fiddling around with the screen buffer and have written a routine to scan the screenbuffer into upper ram and then write it back in upside…

    ... to scan the screenbuffer into upper ram and then write it back ... and write all the start addresses...

    Hope this helps ...
    miskox miskox February 2006 Sinclair Basic
  • Blowtorch method of Speccy repairsI just did my first Spectrum repair (and successful at that). It was the Issue 2 spectrum I wrote about a while ago, I just hadn't got around to doin…

    ... tests on keyboard, sound, ULA, RAM chips, and ROM mostly.
    certain it works 99%.
    It ... commands, weird huh?), one bad upper RAM chip and finally one (the ...
    gtsamour gtsamour January 2007 Hardware
  • Dead Spectrum +Hi all, I've recently dug out my old Spectrum + with the idea of repairing it. When I last looked at it, when I was much younger, I was soldering a …

    ... chip enable logic for the upper RAM (I think it's IC25 ... be wrong) first for testing upper RAM, since this will disable it ... test in the cases where upper RAM is merely returning bad data ... testing expansion card for testing certain classes of faults, probably with ...
    Winston Winston March 2007 Hardware
  • Poorly Spectrum + Fault diagnosis help needed!Hi, I've got a Spectrum+. Sometime in the past I broke it and sent it off to be fixed. It came back working good as new, but with an issue 2 board i…

    ... (or a 48K with bad upper RAM), the machine stack. These ... getting hot. Especially the 4116 RAM chips. Change any 4116 ... br />
    4) Test upper RAM - sometimes, bad upper RAM just stops working so ... to disagree with me on certain issues. Thing is, it ...
    DEATH DEATH July 2007 Hardware
<1234567…34>

Latest Posts

  • I bought an accoustic guitar. How do you play it?
    dm_boozefreek on 7:51PM
  • Goodbye Z80
    zx1 on 7:11PM
  • Happy 40th Birthday to the Amstrad CPC464!
    AndyC on 6:29PM
  • Another Birthday! The Game Boy Is 35!
    dm_boozefreek on 6:17PM
  • I am currently watching.....
    Antiriad2097 on 5:05PM
  • European Software Titles with an English version
    harriusherbartio on 12:06PM
  • How Do You Categorize Your Speccy Software and Games?
    harriusherbartio on 11:21AM
  • Fixed Speccy Software. And which games remained unfixed?
    harriusherbartio on 11:01AM
  • New video about S-video modification on Issue two 48K Spectrum.
    Renegade on April 21
  • Elusive Strategy Games done by the Smaller or less Prolific Software Houses.
    harriusherbartio on April 21

HitBox

Word Docs Hits
upper 2.8K 3.7K
ram 12.6K 21.4K
certain 9.4K 10.2K
addresses 2.5K 3.2K

Related Threads

  • Alternative chips for upper RAM blockDoes anybody know of a way to use 4464 chips instead of 4164 for the upper RAM block in a 48K machine? If not 4464 then something a little more avai…
  • Looking for some 48k RAM (upper 32k bank)Greetings,<br /> I was wondering where I could find some upper RAM for a 48k (issue 4A).<br /> It's the Texas Instruments TMS4532-20NL4 P8419 (or …
  • 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.<b…
  • Inefficient code in ROM, from ram-check to RAM-DONEHere is the inefficient code:<br /> <br /> [CODE]<br /> ;; ram-check<br /> L11DA: LD H,D ; Transfer the top value to the HL registe…
  • Replacing Upper RAM in 48KHi Folks<br /> <br /> Well, my fun continues :) After sorting the display issues with this machine I found I couldn't load software meant for 48K mac…
  • 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…
  • 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.<br /> <br /> When the machine is without the Divide …
  • POKEs on 128K "upper RAM"?I've been working lately with some 128k games, and I've got this question about RAM in games.<br /> <br /> I guess most games use RAM pages 5 and 2 t…
  • Issue 2 Upper Ram, Loading & ResettingI have a 48k Issue 2 Speccy and for the life of me can't track down what the problem is with it. I initially thought that some of the uppe ram ic's w…
  • 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. <br /> <br /> It was labelled as 'keyboard…

Related Searches

  • basic upper lower case
  • basic change upper lower case
  • rom to ram
  • modern ram
  • disable uper ram
  • disable upper ram
  • 150ns upper ram
  • upper ram failure
  • upper ram failure 16k
  • upper ram failure 16kb
  • upper ram failure multiplex
  • upper ram 16k
  • upper ram 85 170
  • upper ram addresses
  • upper ram chips
  • upper ram
  • upper ram 2a
  • upper ram 2b
  • 48k upper ram problem
  • upper ram not detected

Copyright © 2024 World of Spectrum