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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…
... ="http://zx.zigg.net/LRR/"]lower RAM replacement module[/URL], there have ... similar for the upper 32K RAM in a Spectrum.[/QUOTE]
Mirroring UDG'sJust wondered is there a quick an easy way of mirroring UDGs (byte values)? i.e. BIN 11110000 becoming 00001111 etc.
... it by hand, I'm not seeing it work. Even at that ...Mirroring UDG'sJust wondered is there a quick an easy way of mirroring UDGs (byte values)? i.e. BIN 11110000 becoming 00001111 etc.
[QUOTE=Gedlion;717490]That said, looking it over again, when I do it by hand, I'm not seeing it work. Even at that ;a=GBADCFEH stage - I don't seem to get those bits...[/QUOTE]
me.. in the same mode! @work by hand!Repairing a torn trace on an Issue 2 PCBI've found what I think could be the reason for my Issue 2 board not working properly... There is a torn PCB trace beneath one end of where a new ULA…
... be anything wrong with the lower RAM (i.e. none of the ... and like yourself replaced the lower RAM and caps: [url]http://www ...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…
... cartridge works, I'd say lower RAM - it's certainly the place ... - 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…
All black paper isn't the most common symptom of faulty lower RAM, but it can happen.
I could probably have a very good guess at what is wrong if I knew what 'bad address line 0' means and what test was used to determine that.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…
... diags were also failing the lower 16K tests, even though they ... the pattern (I suspected a lower RAM multiplexing issue), once these were ... evicted and replaced the lower 16K tests passed.
RAM chips as dead, these were ...Spectrum 48k video and keyboard issueHi all, few days ago I experimented with battery supply for my speccy (48k issue 2), and I was measuring the voltage and how much current it used. A…
... rather like two) of the lower RAM ICs is faulty, though it ... happens when one of the RAM ICs is poorly seated in ...Spectrum 48k video and keyboard issueHi all, few days ago I experimented with battery supply for my speccy (48k issue 2), and I was measuring the voltage and how much current it used. A…
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Of course, if the lower RAM is faulty, the Spectrum's ...Can a guy that traveled on the short bus learn machine code...Hmmm So after some soul searching I figured it was time to finaly nail spectrum machine code. Its so frustrating to sit infront of a basic listing w…
... .:sad:
I am not a genius, the documentation makes ... examples.
I am not seeing the productivity increase in these ...Can a guy that traveled on the short bus learn machine code...Hmmm So after some soul searching I figured it was time to finaly nail spectrum machine code. Its so frustrating to sit infront of a basic listing w…
... /> [QUOTE=wibble;721116]I am not seeing the productivity increase in these ...I am currently playing......Don't know if there's been a thread like this, but I can't find one.... Having seen all the different threads asking people if they've played such a…
... was especially annoying in multiplayer not seeing the cards because in single ...Another broken SpeccyHi all I have been given another ZX Spectrum, this time it has a really odd problem as you can see in the video: [URL="http://youtu.be/ZOSiBEYQD7w"…
That's exactly what happens when the lower RAM is completely missing. Have you checked that all the power supply voltages are present?Another broken SpeccyHi all I have been given another ZX Spectrum, this time it has a really odd problem as you can see in the video: [URL="http://youtu.be/ZOSiBEYQD7w"…
... exactly what happens when the lower RAM is completely missing. Have you ...Another broken SpeccyHi all I have been given another ZX Spectrum, this time it has a really odd problem as you can see in the video: [URL="http://youtu.be/ZOSiBEYQD7w"…
... need to check the 4116 lower RAM chips to make sure that ...Spectrum 48k unstable Colours on Composite Video OutputHi, I?ve an Speccy 48k here which has an Composite Video Out Mod (The Video-Modulators power input is cut from the board). On this I get an unstabl…
... from the ULA accessing the lower RAM, then that's what would ...FREL Comcon Programmable Joystick Interface not working on 128k but on 48kAnother day, another problem :-) My FREL Comcon Programmable Joystick Interface [url]http://www.worldofspectrum.org/infoseekid.cgi?id=1000070[/url]…
... multiplex the video RAM. The Z80, ROM, upper RAM and edge connector ... on one side, and the lower RAM and the ULA are on ... multiplexing logic for the contended ram so the resistors are no ...SCREEN$ bug fixI've been using the SCREEN$() function recently for reading data off the screen rather than taking up space with an array and I got fed up with the s…
... this ambiguity which I'm not seeing.
extract from Move_Mg_SCRdol ... the screen character,
;if not use the inverse character code ...Issue 3 board with strange piggy-back boardIn case you are interested. I?ve never seen something like this before. I have an Issue 3 board here. When I opened the case and found a strange pig…
... the datasheet of 16kb lower RAM -5v and 12v must ... risk to destroy the Ram Chips during measuring and ... remove power from the ram chips and then start ... solder the powerlines to the ram chips again.
Using ... never killed one single Ram chip. But as usual ...Issue 3 board with strange piggy-back boardIn case you are interested. I?ve never seen something like this before. I have an Issue 3 board here. When I opened the case and found a strange pig…
... to the datasheet of 16kb lower RAM -5v and 12v must be ... +12V.
So the RAM *should* be okay if the ...First time capacitor replacementHi, I have an Issue 2 board, that i wish to start with recapping as advised on here, as they look to be all original. (Same with V3 board, but going…
10.4 V could be OK, but it's a bit further off than usual. I'd still suspect a problem with the lower RAM or its power supply.First time capacitor replacementHi, I have an Issue 2 board, that i wish to start with recapping as advised on here, as they look to be all original. (Same with V3 board, but going…
... the typical pattern of a lower RAM failure any more.
RAM area.
You could ...Issue 3 board with strange piggy-back boardIn case you are interested. I?ve never seen something like this before. I have an Issue 3 board here. When I opened the case and found a strange pig…
... ] So what to check next, Ram chips or address logic chips ... to differ between ROM and lower RAM.Black Screen Spectrum 48kWas working ok, it came to me in a Fuller FDS keyboard, I had a nose inside and found a floating power lead connected to the keyboard, I removed that…
... off the +5v on the lower RAM chips and presume put it ...32K Expansion board for issue 1 SpectrumI realise these are as rare as rocking horse poo, but I'd really like to upgrade my issue 1 and use it a bit more than is possible currently. Don't …
... does the replacement for the lower ram.. he also does one that ... does upper ram or did.. I was supposed ... the sales bit for lower ram or low ram, or "sell my retro ...Getting close to a release: Android SpectaculatorJust a few more bits to tidy up then I'm done :) [IMG]http://www.spectaculator.com/download/misc/PlayStore.jpg[/IMG] Should mean people can top sen…
... the refresh button but its not seeing my games. It has created ... on the internal sdcard but not the external one where I ...Getting close to a release: Android SpectaculatorJust a few more bits to tidy up then I'm done :) [IMG]http://www.spectaculator.com/download/misc/PlayStore.jpg[/IMG] Should mean people can top sen…
... the refresh button but its not seeing my games. It has created ... on the internal sdcard but not the external one where I ...Born again Speccy user with problemsHello all, Firstly I'd like to say a big hello - this is my first post! When I was 8 or 9 or so my dad bought a ZX Spectrum 48K and a whole bunch o…
... eagerly await your upper and lower RAM modules![/QUOTE]
They'll ... ; one for BEEPing and another (lower one) for saving. It is ...Elite Kickstarter ProjectAs some of may know Steve Wilcox of Elite is currently close to raising ?60k via Kickstarter to begin manufacturing a USB spectrum keyboard. I have g…
Makes me wonder how Elite would react to someone flogging their games without permission & not seeing a bean in return.Faulty 48+Hi I picked up a pile of Spectrum kit including a boxed "untested" 48k+ The Speccy boots to this screen... [IMG]http://www.scotek.net/zx spectrum/…
Smells like a lower RAM fault to me - magenta and blue bars to me would suggest an issue with either IC6 or IC7.
As for the joystick interface, a picture would paint a thousand words :)
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