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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 ... -
Pimping an Issue 4SSo theres this 4S I have, its been a pain in the backside for ages, this and that going wrong then I stupidly broke it properly by inserting a keyles…
I was waiting the upper ram module to come out but I don't see it being sold on ebay.... Has it officially come out? -
Pimping an Issue 4SSo theres this 4S I have, its been a pain in the backside for ages, this and that going wrong then I stupidly broke it properly by inserting a keyles…
... ;715819]I was waiting the upper ram module to come out but ... paypal notes that its the upper RAM youre after and he will ... -
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…
[QUOTE=Zorn;713737]
I would think that so long as the CPU isn't executing anything from upper RAM....[/QUOTE]
Or the machine stack? -
Issue 4A black paper, white borderJust had one of these through, nice yellow pcb! Everything but the ULA soldered in. On power up I get black paper, white border and some intermitten…
... works, I'd say lower RAM - it's certainly the place ... is - I forget) that disables upper RAM to check if it suddenly ... />
Desolder all the lower RAM, then socket it, now you ... -
Issue 4A black paper, white borderJust had one of these through, nice yellow pcb! Everything but the ULA soldered in. On power up I get black paper, white border and some intermitten…
... />
Perhaps it means a RAM addressing error was detected, i ... , suggest a fault affecting the upper RAM, but I don't think ... -
Corrupt paper on zx spectrum 48kHi. When I power up my spectrum (issue 3) I get the light grey border, but the paper is black and it switches between thin red vertical lines and thi…
... up of two groups of RAM chips.
The so ... called lower RAM (used for the screen so ... sometimes called the screen RAM) is made from eight ... />
The so called upper RAM also uses eight DRAM chips ... fault finding a suspected RAM fault is to use ... -
Barn find #4I think this is some sort of backup device. Its got "007" on the motherboard and the mice have chewed the buttons. Will do a little research later in…
... MC-routine must run in RAM. The paging circumstances (an address ... copy content of ROM to upper RAM and then "emulate" NMI jump ... -
Diodes placed the opposite way in +2A/+3 PCB'sI was just going to report this as a mistake in the schematics drawn by Guesser, but I saw a real board and realize that the schematics are right. […
... 0x00,0x01,0x02 to the upper ram address it actually uses 0xff ... -
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…
Just ordered an upper ram module :) My low power consumption Speccy will be complete now. -
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…
... pattern (I suspected a lower RAM multiplexing issue), once these were ... /> However the upper tests revealed 4 of the upper RAM chips as dead ... -
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…
... /> However the upper tests revealed 4 of the upper RAM chips as dead ... -
RCS (Reverse Computer Screen)[B]RCS[/B] ("Reverse Computer Screen", or simply SCR written backwards) is a small utility I'm about to release, that reorders bytes from the ZX-Spec…
... RCS'ed screen stored in upper RAM, trying the buffered routine to ... -
When is a 16k not a 16k ?Can anyone explain what this machine is supposed to be ? Speccy with a 16K sticker on the base. Doing a peek 23733 returns 255 so a 48K ? Opened …
... factory bodged to use OKI upper RAM (soldered in place), but I ... -
When is a 16k not a 16k ?Can anyone explain what this machine is supposed to be ? Speccy with a 16K sticker on the base. Doing a peek 23733 returns 255 so a 48K ? Opened …
... is not true. If the upper RAM is absent or completely faulty ... that faulty, but somewhat functioning RAM is present in the computer. -
When is a 16k not a 16k ?Can anyone explain what this machine is supposed to be ? Speccy with a 16K sticker on the base. Doing a peek 23733 returns 255 so a 48K ? Opened …
... ) a 16K machine. Course, all upper RAM may have been removed before ... -
When is a 16k not a 16k ?Can anyone explain what this machine is supposed to be ? Speccy with a 16K sticker on the base. Doing a peek 23733 returns 255 so a 48K ? Opened …
... multiplexor connections to support OKI upper RAM. By default, the issue 2 ... only supportsTI RAM. It's all to do ... /showthread.php?t=44503#1"]upper RAM module[/URL]. -
When is a 16k not a 16k ?Can anyone explain what this machine is supposed to be ? Speccy with a 16K sticker on the base. Doing a peek 23733 returns 255 so a 48K ? Opened …
... multiplexor connections to support OKI upper RAM. By default, the issue 2 ... only supportsTI RAM. It's all to do ... /showthread.php?t=44503#1"]upper RAM module[/URL].[/QUOTE]
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 …
... particular its interaction with the upper RAM.
If the Spectrum ... discovered between it and the upper RAM module.
If a ... , I will send them an upper RAM module. It would be good ...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 …
... of them attempt to address upper RAM through hardware. They appear ... very unlikely to me the upper RAM module would interfere with ... capacitors) that disrupts the new upper RAM?
It looks ... with a Spectrum with the upper RAM module; I use software ...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 …
... of them attempt to address upper RAM through hardware. They appear ... very unlikely to me the upper RAM module would interfere with ... capacitors) that disrupts the new upper RAM?
It looks ... with a Spectrum with the upper RAM module; I use software ...
