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48K 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…
That points to a bit 1 error in both lower and upper RAM, so replace IC7 (lower RAM, 4116) and IC16 (upper RAM, 4532 but replace with 4164).
B -
48K 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…
... d start with the upper RAM first, to be honest. ... I'd expect if the lower RAM were bad. Plus the ... programs fine without an upper RAM chip so easier to ... just remove the D1 upper RAM chip and leave it running ... the problem is in the lower RAM. If it doesn't, ... -
48K 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…
... ;805419]I rather suspect the lower RAM test failed because of IC16 ... thought that if an upper RAM IC was interfering with the ... with just changing the upper RAM IC and replacing with a ... -
48K 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…
... =whoremoan;806182]However! Ran the lower memory test again and it ... the contents of lower RAM. It could be a lower RAM IC with an ... -
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…
... loaded from tape if your lower RAM is working ok, [URL="http ... first to isolate the upper RAM though.
B -
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…
I downloaded Zorns RAM tester program a while back ... be at fault and not the upper RAM. Swapped the ULA over ... Issue 2 and run the ram test program again with the ... and changing a few Upper RAM IC's, run the test ... -
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…
Try changing the lower RAM on D7 too, sometimes chips can affect each other in odd ways. Otherwise it sounds like a bit if solder somewhere it shouldn't be on the upper D7 line. -
Speccy Vs Amstrad CPC Vs C64I hope no one minds me posting this here as well as in the announcements section. I'll delete it if there is a problem. It's childish fun but can I …
... was scrolling, and the C64.. not having per pixel colour, which ... was fine too. I'm not seeing what you are saying to ... of game, which also does not preclude any of the other ... /> I guess my point is not so much to say that ... -
Things you only figured out after all these years.Its funny isn't it when for almost all your life you believe something to be true, and then after all these years realize it's not true, or never hap…
... couple of weeks ago after not seeing it for years, and it ... -
Double keystrokes on zx spectrumHappy New Year everyone. I have this spectrum 48k issue 3b I?ve been working on now and then. I have replaced upper rams, installed a lower ram repla…
Now I have tried the lower ram module in another Spectrum and it worked fine, so I think that rules it out as dodgy. But thank you for your highly qualified guess though. -
48K Not booting properlyBought another faulty spectrum from Ebay. This one, when you turn it on, it looks like it's going to boot OK, but when it gets to the point where it…
... line with the bad upper RAM chip.
If you ... -5V is lower than -4V then it's probably upper RAM. If ... it's probably a bad lower RAM chip or electrolytic capacitors.
Switched voltage regulatorIn the past a replacement voor the (hot!) 7805 has popped up a couple of times in various threads. As far as I know, Recom Power Inc. was always ment…
... the -5V line for the lower RAM. Therefore, I recommend to insert ...48k ProblemsBought in a 48k at work just before christmas. Nice machine, boxed (box has seen better days) and i'm presuming it's an issue 1 machine (001-596759.…
Sounds like lower RAM and bad caps.
Test voltages and report back..48k ProblemsBought in a 48k at work just before christmas. Nice machine, boxed (box has seen better days) and i'm presuming it's an issue 1 machine (001-596759.…
Yes, check the lower RAM for -5V and +12V.
And that should be an issue 3, with that number.48k issue 2 video issueHi folks. I am currently tring to fix an issue 2 board. I was getting the yellow greenish screen. (also there there is a lower ram fault with it i th…
... and changed some of the lower ram and still getting the odd ...48k issue 2 video issueHi folks. I am currently tring to fix an issue 2 board. I was getting the yellow greenish screen. (also there there is a lower ram fault with it i th…
... out with reasonable certainty which lower RAM IC is at fault. (See ... ] post where I diagnosed a lower RAM issue the same way.)
48k issue 2 video issueHi folks. I am currently tring to fix an issue 2 board. I was getting the yellow greenish screen. (also there there is a lower ram fault with it i th…
... just checked the voltages on lower RAM IC 13 and they do ...Dodgey R62 / D16 on Issue 2?Hello all, I am still beavering away trying to work out why my Issue 2 fails and after a much closer visual inspection I noticed what looks like som…
... />
If one of the lower RAM IC's were dead I ...48k ProblemsBought in a 48k at work just before christmas. Nice machine, boxed (box has seen better days) and i'm presuming it's an issue 1 machine (001-596759.…
[QUOTE=DEATH;812695]Sounds like lower RAM and bad caps.
Test voltages and report back..[/QUOTE]
But also a ROM failure or a 32K RAM bank failure, since it goes past the RAM test routine and prints the copyright message.Joytsick Interface damaged SpectrumHello All, Sob.. I am a plonker, I did the cardinal sin, I was testing a bunch of joystick interfaces that I got off ebay and one didn't have the ke…
... , I'd remove ALL the lower RAM chips, make sure there are ... the correct voltages, then replace RAM chips with sockets, and replace ... with one of Zorn's lower RAM boards and just pray you ... don't need an upper RAM board too.
A ...Newbie with a faultHi all just joined after digging my spectrum out of the loft after 30 years, it was put up there because it had a common fault I remember from back i…
... from one or more faulty lower RAM ICs, possibly caused by failure ...Newbie with a faultHi all just joined after digging my spectrum out of the loft after 30 years, it was put up there because it had a common fault I remember from back i…
... it be the Cpu and lower ram for instance, or Cpu and ...GOING FOR GOOD.I'm ****'d off with stuff. I'm off and I'm not going to post anymore. Bye.
... missing something, but i'm not seeing much of a demise here.GOING FOR GOOD.I'm ****'d off with stuff. I'm off and I'm not going to post anymore. Bye.
... missing something, but i'm not seeing much of a demise here ... all five" - you're certainly not on your own there (although ...What influence the number of stripes during initialization?Hi for All! After some adventures, with other rare old computers I'm back here to my favourite forum. :) Recently I got some ISSUE 2 boards from Ben…
... with 5C102E ULA and NEC RAM that shows four stripes when ... Issue 1 board with MM5209N lower RAM produces the following display:
lower RAM IC's installed in a ... associate encountering MM5209 and NEC RAM with very early machines, and ...What influence the number of stripes during initialization?Hi for All! After some adventures, with other rare old computers I'm back here to my favourite forum. :) Recently I got some ISSUE 2 boards from Ben…
I've checked the RAM types in the ISSUE 1 boards which also showed four stripes as the particular ISSUE 2 board. Both of them contained also NEC lower RAM. It looks like that there is a correlation... Thank you!Finally got round to itFinally got round to giving my old speccy a close look. Details 1982 Issue 2 Seriel No 001 196193 Hmm... Followed the initial tests on You tube w…
... on sockets and all the lower RAM soldered to the board - my ...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 ...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 ...
