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Flashing coloured blocks - diagnosisHiya, hope this is the right place for this... Was given an Issue 2 48K by a someone yesterday that hasn't been powered on in 20 years, which works …
... it successfully checks the lower RAM?[/QUOTE]
It's ... -up test doesn't identify upper RAM as faulty and then the ... 't help either if the upper RAM interferes on the data bus ... 1 and 7 in the upper RAM and I believe those are ... -
Flashing coloured blocks - diagnosisHiya, hope this is the right place for this... Was given an Issue 2 48K by a someone yesterday that hasn't been powered on in 20 years, which works …
... I think replacing the faulty RAM will solve the problem.
The RAM chips are responsible for dealing ... for the lower RAM and another two for the upper. The other ... generating control signals for the upper RAM.
Also, once ... -
128k Basic used much ?Hi - I was wondering if there were many,if any, games programmed in 128k basic? I was also thinking of doing one myself as I wish to make a text heav…
... one basic program that uses ram disk, but for a screen ... 'm sure you can use ram disk, so you'll get ... read the text directy from upper ram with PEEK rather than using ... -
What do this modification ?Hi All, I get from ebay black 2a, I open to clean case and show ... this [IMG]http://forest.no-ip.org/wos/2a.jpg[/IMG] what do this modification ? …
... = 169ns . Are original ROMs 150ns chips?
- RAM timmings are handled by ... -
Faulty 48K Issue 3 motherboardHi I have a faulty Issue 3 motherboard and would appreciate it if somebody can steer me in the right direction of where to begin with the fault find…
... black screen. I removed the upper RAM and interface chips so that ... start again:
- Quit upper ram
- Power on.
- Check ... +5v, +12v, -5v in lower ram.
- If spectrum doesn't ... -
Issue 3 board... How to resurrect?Dear Everyone, Now I have a working 48k Issue 3, a sort of working Speccy+ (still having problems with the keyboard, more of that in another post) a…
... typical fault in the lower RAM isn't the cause of ... quite common for a faulty upper RAM IC to interfere on the ... 16K model. Sometimes a failed RAM IC develops a short between ... set of measurements. Remove any RAM IC that gives an usually ... -
Covertape speedloaderThere was a covertape (possibly YS) that had a speed loader / saver routine included on it. It stood out to me as I recall it had a counter on it, co…
... the ROM tape routines to upper RAM, make any adjustments for jump ... -
Issue 3 board... How to resurrect?Dear Everyone, Now I have a working 48k Issue 3, a sort of working Speccy+ (still having problems with the keyboard, more of that in another post) a…
... with the lower RAM chips, and sometimes with the upper RAM chips. Occasionally ... -
another faulty zx spectrum +2 to fix!!!Hello to all, I'm new here... I have got a faulty +2 (gray) and start to try fix it... I have read the treads of xaris_sm and Pluto63 as background…
... for lower and one for upper ram.
Also connected were a ... .
I also connected a RAM Turbo with Paul Farrow's ... demos, some games and the RAM tester from Paul Farrow.
Cascading transistorsMiguel (mcleod_ideafix) alerted me on an aspect of a design I'm working on where I am cascading transistors, which may give problems. This is the par…
... display the image. ROM and upper RAM are also available at this ... supply rails to feed lower RAM. The DC-DC converter uses ... data from nowhere because lower RAM won't be ready before ... +5V rail, ULA and lower RAM are ready and working, the ...48k Rubber Key Spectrum ProblemI'm testing my mate's spectrum that hasn't been used since the late 80's. Unfortunately, it seems to keep randomly resetting itself (like pressing th…
... throw up any errors in upper RAM. After a few hours of ...ZX-Spectrum 16KWanted working 16K machine for reasonable price I'm located in NY, U.S.A. Thanks!
... . It has sockets where the upper RAM and necessary support ICs could ...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…
... =mcleod_ideafix;709022]Although non-contended RAM (4532 chips) seem to be ... more Spectrums that have upper RAM faults than lower RAM faults. Perhaps because ...Issue 2 black paper white borderGot an issue 2 here that has a 6c001e ULA, no cockroach, no transistor mod (although you can clearly see on the top of the z80 and on some legs, some…
Turned out to be upper RAM data line 2! All sorted now16K/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…
Is it possible to make a little board like this for the upper ram as well?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…
[QUOTE=gtsamour;711322]Is it possible to make a little board like this for the upper ram as well?[/QUOTE]
Yes. Please wait for further information...ZX Spectrum 48K working as 16K from factoryGood morning I Have a Zx Spectrum 48k working as 16K , it came like this from factory. What can i do to solve this , and put it to work as 48K? Wha…
... how the Spectrum ROM's RAM test routine works).
upper RAM.ZX Spectrum 48K working as 16K from factoryGood morning I Have a Zx Spectrum 48k working as 16K , it came like this from factory. What can i do to solve this , and put it to work as 48K? Wha…
... 48K Spectrum with faulty upper RAM, but the initial RAM test routine passes ... a few bytes) of the upper RAM. All sorts of strange things ...ZX Spectrum 48K working as 16K from factoryGood morning I Have a Zx Spectrum 48k working as 16K , it came like this from factory. What can i do to solve this , and put it to work as 48K? Wha…
... one or more of the upper RAM ICs (most likely) or perhaps ... />
(Tell it to test upper RAM.)
You might also ... POKE and PEEK in the upper RAM - search through the forums or ...ZX Spectrum 48K working as 16K from factoryGood morning I Have a Zx Spectrum 48k working as 16K , it came like this from factory. What can i do to solve this , and put it to work as 48K? Wha…
... method doesn't always reveal upper RAM faults, but it's worth ...ZX Spectrum 48K working as 16K from factoryGood morning I Have a Zx Spectrum 48k working as 16K , it came like this from factory. What can i do to solve this , and put it to work as 48K? Wha…
... too seems to have faulty upper RAM.
Update: I've ...ZX Spectrum 48K working as 16K from factoryGood morning I Have a Zx Spectrum 48k working as 16K , it came like this from factory. What can i do to solve this , and put it to work as 48K? Wha…
Upper RAM, 4164 chips, get em from ... , but if you search "4164 RAM", you'll get several listings ... an edit:
Lower RAM are 4116 chips, same source ...ZX Spectrum 48K working as 16K from factoryGood morning I Have a Zx Spectrum 48k working as 16K , it came like this from factory. What can i do to solve this , and put it to work as 48K? Wha…
... the /RAS signals for the upper RAM and so the ROM code ... only the lower 16K of RAM. The output of the voltage ... wire touch anything else." The RAM test program would probably then ...ZX Spectrum 48K working as 16K from factoryGood morning I Have a Zx Spectrum 48k working as 16K , it came like this from factory. What can i do to solve this , and put it to work as 48K? Wha…
... high. Bit 5 in all upper RAM is provided by IC20 (the ... got a lot of faulty upper RAM ICs, you might consider waiting ... month I should have an upper RAM version of [URL="http://zx ...ZX Spectrum 48K working as 16K from factoryGood morning I Have a Zx Spectrum 48k working as 16K , it came like this from factory. What can i do to solve this , and put it to work as 48K? Wha…
I will change the IC20 then.
In case of putting a upper ram module, do you send to Portugal?ZX Spectrum 48K working as 16K from factoryGood morning I Have a Zx Spectrum 48k working as 16K , it came like this from factory. What can i do to solve this , and put it to work as 48K? Wha…
[QUOTE=camaisin;712351]In case of putting a upper ram module, do you send to Portugal?[/QUOTE]
Yes. Prices will probably be the same or very similar to those for the lower RAM module.Issue 2 crashes after about 30 minsHi Guys, I have an Issue 2 zx spectrum that seems to get graphic corruption after about half hour of playing, then finally falls over and crashes. …
... version of the ZX Spectrum upper RAM module is working on the ...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…
... you can disable the extra ram , with a switch.. either on ... 0V (normal operation) or 5V (upper RAM disabled). In the disabled state ... could map itself into the upper 32K if it wanted to ...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…
... isn't executing anything from upper RAM, this switch could be operated ... without any ill effect. The upper RAM should even retain its contents ...Rubber Key RAM - Repair?Hello there everyone! I'm a long-time lurker on here - ROMs, documentation etc. but yesterday I finally ponied up for my own speccy, just like the on…
... (although if more than one upper RAM chip is down we might ...
