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Amperage drastic reduction in a rubber 48KWell, I am now with the approach of a drastic reduction ZXSpectrum amperage. As a first step would change the Z80 processor for other (Z80C). Unfortu…
... got rid of the crappy lower ram chips.[/QUOTE]
I ... fix removing the 8 integrated lower memory, IC25 & 26 and ... -
Amperage drastic reduction in a rubber 48KWell, I am now with the approach of a drastic reduction ZXSpectrum amperage. As a first step would change the Z80 processor for other (Z80C). Unfortu…
... got rid of the crappy lower ram chips.[/QUOTE]
No ... -
ZX Spectrum 48k issue 3b power problem?Hi :) I was lucky enough to find a couple of ZX Spectrums at a car boot sale yesterday. I spent the evening fiddling about with one (issue 2) and t…
... problem ( very strange) maybe a lower ram problem. The last spectrum I ... . The problem was a faultly ram chip 4116.
Bye ... -
ZX Spectrum 48k issue 3b power problem?Hi :) I was lucky enough to find a couple of ZX Spectrums at a car boot sale yesterday. I spent the evening fiddling about with one (issue 2) and t…
... problem ( very strange) maybe a lower ram problem. The last spectrum I ... . The problem was a faultly ram chip 4116.
Bye ... do I check whether the ram 4116 chips are working okay ... -
Spectrums with gold RAM chips?Hey people, This is a first for me: [img]http://www.mutant-caterpillar.co.uk/ian_stuff/blingspeccy.jpg[/img] Is it normal to have gold RAM chips? …
I have one of such spectrums too, but lower RAM is defect.. Looks pretty. But never seen them in Issue 3 onward boards. -
Spectrum+ fault - lines on boot screen, freezesThe ZX Spectrum+ I bought in the car boot has a fault. When you boot it, it's displaying the Copyright screen, but each character position has a vert…
... the machine powered up, the lower RAM (4116 memory) can become faulty ... -
Spectrum+ fault - lines on boot screen, freezesThe ZX Spectrum+ I bought in the car boot has a fault. When you boot it, it's displaying the Copyright screen, but each character position has a vert…
... the machine powered up, the lower RAM (4116 memory) can become faulty ... -
rubber key Spectrum 48k problem :(when i plug the spectrum in all i get is a black screen with a red border and sometimes flashing blocks. the spectrum worked until about 20 mins ago…
... ] the voltages on the 16K lower RAM. You should get pin 1 ... you have a dodgy 16K RAM chip. If you have access ... to have to keep remove lower RAM chips until you find the ... -
Rom Cartridge - How does it work?So I've got me an IF2 and it has this ROM cartridge slot. How does it work? I read Paul Farrows site but one question remains unanswered. If I have o…
it replaces the lower ram, or part of it.. thats ... find if you have faulty lower ram 4116(?) chips.. as it's ... -
Rom Cartridge - How does it work?So I've got me an IF2 and it has this ROM cartridge slot. How does it work? I read Paul Farrows site but one question remains unanswered. If I have o…
... =fog;546421]it replaces the lower ram, or part of it.. thats ... find if you have faulty lower ram 4116(?) chips.. as it's ... ZX81, so it cannot replace lower RAM, only lower ROM.
Question: What ... will happen if you replace lower RAM (screen) with ROM? -
Rom Cartridge - How does it work?So I've got me an IF2 and it has this ROM cartridge slot. How does it work? I read Paul Farrows site but one question remains unanswered. If I have o…
... ZX81, so it cannot replace lower RAM, only lower ROM.
Question: What ... will happen if you replace lower RAM (screen) with ROM?[/QUOTE]
RAM (it controls the address and ... -
Spectrum not working, can anyone help this lady?[URL="http://www.retrogamer.net/forum/viewtopic.php?f=6&t=29734#p674152"]http://www.retrogamer.net/forum/viewtopic.php?f=6&t=29734#p674152[/URL]
... 's probably a damaged RAM in the lower bank. If not, it ... rails, and if the 16K lower RAM bank is not being fed ... -
Dead Spectrum SocietySo I'm getting back into real Sinclair computers rather than emulators. During the summer months I was lucky enough to buy a working ZX81 and was giv…
... the lower RAM chips (4116) are quick to die as well. Lower RAM and ... voltage conversion circuitry busted -> lower RAM chips dead (or vice versa ... before trying further tests. The lower RAM chips are a lot more ... -
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…
... problems with the upper 32K RAM. The 'dead cockroach' ... fix & upper 32K RAM are unrelated. I myself ... test program that checks lower RAM, to make sure there ... . A machine with lower 16K RAM okay is better than ... , and fix upper 32K RAM problems.
[*]Be ... -
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…
if ur gonna desolder the ram chips, you will need wick. some peeps like pumps but i could never get results from them. it took me a couple hours to remove the 8 lower ram chips and i broke 2 traces, but after re[lacing with sockets it all seems worthwhile! -
Dead Spectrum SocietySo I'm getting back into real Sinclair computers rather than emulators. During the summer months I was lucky enough to buy a working ZX81 and was giv…
what sort of pattern?
Have you gone through the steps in the repair guide to isolate the lower ram so you can test the supply circuits? If so are you getting all three voltages correct now? -
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…
... shows the default contents of lower RAM, so it causes activity on ... -
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…
... I will next remove the lower RAM and fit sockets. I would ... -
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…
... /> On the other hand: having lower RAM on sockets surely is a ... -
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…
... start the Spectrum with the lower RAM all removed, then the display ... the CPU (still with the lower RAM removed) doesn't have any ... -
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 CPU (still with the lower RAM removed) doesn't have ... br />
With all the lower RAM missing, a "working" Spectrum shows ... />
So, in absence of lower RAM, shorting C27 and leaving it ... seen some schematics about replacinig lower DRAM with SRAM at ... -
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…
... less plain white screen when lower RAM removed? Don't know for ... -
Canny use of the 'r' register?Seeing Sokurah's code in the [URL="http://www.worldofspectrum.org/forums/showthread.php?p=583188#post583188"]crunch sound thread[/URL] has made me th…
... . Probably won't work for lower RAM since ULA is refreshing that ... it's 100% functional (all RAM replaced with SRAM :D ).
Z80 Cross-assemblersI need to build some code which contains sets of routines which run at one address but are stored elsewhere. Unfortunately, neither of the assembler…
... at the top of RAM, copy it to lower RAM, then page the ... original RAM bank back in and ...Z80 Cross-assemblersI need to build some code which contains sets of routines which run at one address but are stored elsewhere. Unfortunately, neither of the assembler…
... at the top of RAM, copy it to lower RAM, then page the ... original RAM bank back in and ...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 Spectrum+ that had faulty lower RAM rather than the one I ...Issue 2 voltage troubleDear all, I got my hands on an old issue 2 from a friend. Price was close to zero so I did not hesitate to take it. After powering it up I was sur…
... 5V, -5V and 12V from lower Ram bank. Target was to see ... whether a faulty ram draws to much current and ... TR4 and thus a faulty lower Ram -> non working Speccy.
Issue 2 voltage troubleDear all, I got my hands on an old issue 2 from a friend. Price was close to zero so I did not hesitate to take it. After powering it up I was sur…
... not caused on consumption side (lower RAM, video circuit), but in production ... very likely to damage the lower RAM when supply voltages are off ...
