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ZX Spectrum Test PCB I recently read about one of these (I think it may have been the Retroleum site but I am not sure) and I thought "What a great idea" . As pictured …
... , most IC's are [b]not[/b] socketed. Meaning: would need ... -in test procedures for lower RAM, upper RAM, etc.
Of course ... .
And working or not, having all IC's socketed ... -
ZX Spectrum Test PCB I recently read about one of these (I think it may have been the Retroleum site but I am not sure) and I thought "What a great idea" . As pictured …
... was done next to the upper RAM sockets. I'll post up ... contents of the ROM did not change on any issue 1 ... -
Spectrum Next in the ArchiveWhen the Spectrum Next is launched, should it be added to the archive, and games archived as per usual WoS usage? There are a lot of new games annou…
... works on 16k speccy but not on a 48k one? ... that that makes sense, not just some contrived case where ... system memory locations. The RAM in the Spectrum is ... from the non-existent "upper" RAM to determine if the ULA ... is reading data from RAM in order to "draw ... -
New AGD videogame: Blimpgeddon by NarwhalJust discovered this game today. No idea the exact day of release, but it doesn't matter. It's something new and developed by this author called Narw…
One thing I've detected... Apparently, there's no way ... -ass beams in the following upper level (not the one we come ... -
ROM emulation in softwareHi, first of all -- I only have shallow / uni knowledge of hardware, electronics, and physics. So forgive me for asking things that are out of that …
... computer does not try to write to the "lower" 16k RAM area ... area of RAM.
If the Z80 is not stopped for ... two long, the "upper" RAM will not have time ... , some (or all) of the "upper" RAM may loose any data stored ... -
ZX Nuvo 128..Hi There, I have built the ZX Nuvo 128 by Superfo, but it has a problem. The machine is working, but the video signal is completely bonkers. I've …
... reports the amount of DivMMC RAM available - not quite what I was ... both return 255 then joystick not detected. If only on port 223 ... port then kempston decoder is not so good (use only A5 ... -
ZX Spectrum 48K it only shows colored barsHello, I'm new to the forum and I need help with a ZX Spectrum 48K which I bought recently unfortunately defective. I want to mention that before t…
... specification.
TR6 is not critical (machine will start without ... the speaker. It's not critical (machine will start ... IC23, to IC26 controls expansion/"upper" RAM (machine will start without it ... As the Spectrum does not officially generate a grey colour ... -
ZX Spectrum 48K it only shows colored barsHello, I'm new to the forum and I need help with a ZX Spectrum 48K which I bought recently unfortunately defective. I want to mention that before t…
... ,C7 and C8 not yet but I do not think it's ... RAMs... unfortunately, it still does not work, but the image changed ... IC23 connected to 5V(deactivation upper RAM ).... no luck... -
Replacing lower RAM 4116 ZX Spectrum 48k - desoldering advice please?A long post, but interesting pictures perhaps. :) I'd like some advice: (also apologies I think I picked the wrong 'Hardware' category for this, plea…
... them all with a lower ram replacement board:-
[url ... 't rule out any faulty upper ram IC's either. I have ... , and IC17 which is a upper ram IC. This has made repairing ... way as yourself, but unfortunately not to great success I'm ... -
Memory Contention: A Hypothetical Fix?I have just had this crazy thought: If one were to wire an additional memory chip, say a 6264 8Kx8 SRAM, in parallel with the main memory so that it …
... bus (with the Z80, upper RAM and ROM). You also have ... the Z80 CPU IS NOT trying to access the ... the lower RAM to some new "screen" RAM during the time ... that the Z80 CPU is not using ... only reads from this new RAM.
This ... -
Replacing lower RAM 4116 ZX Spectrum 48k - desoldering advice please?A long post, but interesting pictures perhaps. :) I'd like some advice: (also apologies I think I picked the wrong 'Hardware' category for this, plea…
... 't rule out any faulty upper ram IC's either.[/quote]
ram ICs were broken. I only ... started (knowing it'll probably not fix it) or pack everything ... sell it as a fixer-upper with the new chips, new ... -
What's going on inside this ZX Spectrum? [Newbie]Hello folks Last year I got hold of a ZX Spectrum. At the time it appeared to boot up fine, but more recently when I've tried to boot up I've had…
... I suspect it is not related to the fault ... . One or more faulty upper RAM ICs interfering on the data ... Faulty lower RAM. The most common lower RAM faults don't ... 5. Faulty ROM (rare, so not very likely).
... lead to the lower RAM being damaged. Be aware ... -
Replacing lower RAM 4116 ZX Spectrum 48k - desoldering advice please?A long post, but interesting pictures perhaps. :) I'd like some advice: (also apologies I think I picked the wrong 'Hardware' category for this, plea…
... If the -5V is not good, don't leave powered ... has failed, there is not much point in continuing unless ... /> If the border does not go white (can appear to ... Z80 CPU is either not able to run the ... may be worthwhile disabling the "upper" RAM, then retesting (ask for ... -
Troubleshooting my +2To put this in context: a while back (i.e. late last year and earlier this year) I was looking to put together a compilation of modern Spectrum games…
... socket.
Most (but not all) DRAM chip faults, take ... ), or all memory above 32k (upper RAM) including any non-contended banks ... -
Troubleshooting my +2To put this in context: a while back (i.e. late last year and earlier this year) I was looking to put together a compilation of modern Spectrum games…
... /> [quote="1024MAK;925686"]Most (but not all) DRAM chip faults, take ... ), or all memory above 32k (upper RAM) including any non-contended banks ... of use for, were it not for one problem - I don ... -
Spectrum +2 grey ear mod?Is it possible to turn the sound port on the back of a grey Spectrum +2 into an ear input? I know it's possible for the black +2 but I can't find muc…
... can map ROM and RAM throughout the Z80 CPU ... area of upper RAM in the memory map must not respond to ... CPU instruction fetches, instead the RAM ... from the area of upper RAM in the memory map. ... increase the amount of RAM available to BASIC. But ... -
problem loading/playing gameshello to all! i was last active at this forum 11 years ago, and here goes the same thing :) found my old speccy, did the composite mod, managed to …
... ="Ast_A_Moore;927726"]No, the lower RAM is there. It’s the ... the lower left corner. The upper RAM and at least three other ... some of the chips are not working since i have the ... -
48k packed up after cap changeHi all, I'm relatively new to the Sinclair world, my 8-bit repairs in past was lurking in the dark sides of Acorn, Amstrad and Commodore! I've got…
... functional (it reads screen RAM and creates the video ... The Z80 CPU is not processing instructions from the ... all in the lower RAM area, which had been ... noted that a failing upper RAM IC can interfere with ... should also remove the upper 32k before I continue ... -
Fixing a poorly Issue 3 - Odd faults.Here's one for you Spectrum fixers, I warn you it's a long one. I've spent a couple hours this evening doing several repairs on a rubber keyed Speccy…
... the machine passed lower and upper ram tests. Switched on without SMART ... corruption. The beeper is still not working but that might be ... a spare one those lower ram modules, I may replace all ... might be a cracked track not noticeable/hidden under a component ... -
what components normally get taken out if you plug+unplug a joystick interface in with the power onwhat components normally get taken out if you plug+unplug a joystick interface in with the power on? i remember doing this a few times when i had …
... either of the lower or upper ram ic's. It can also ... circuit. It would vary and not be down to a single ... -
48K Issue 2 RAM issuesI have 48K issue 2 board (I've checked, the upper memory is present!). It's not very well. I've not attempted to diagnose one before, so please bear …
... in one location in the upper RAM. Then asking the CPU ... on screen. If the RAM was working correctly, you ... /BASIC).
The upper RAM is made up of eight ... or powered on, is NOT a full memory test. ... from the highest possible RAM address down to the ... -
More on the Cheetah RampackI should be more careful about doing "repeats" ( I should learn some manners) but I could not find anything recent on these . But here is on WOS …
... to see "Lower RAM error at 57FFB " And "32K Upper Ram OK" ( I ... OK) .Then it said "Lower Ram error encountered ". Two of the ... those two ICs. I was not sure if it was listing ... about the Cheetah.(It is not a "dirt rotten cheetah" after ... -
The Different Approaches To Upgrading the ZX Spectrum from 16K to 48K This is probably something that has been covered before . I will take a look to see if I can find anything on WOS
... internal upgrade on ? I do not know . I am just ... />
And here the "upper ram module" is introduced:-
But are "upper Ram modules as good as individual ... uk/computers/zx-spectrum/hardware/ram"]breakintoprogram.co.uk/computers/ ... -
The Different Approaches To Upgrading the ZX Spectrum from 16K to 48K This is probably something that has been covered before . I will take a look to see if I can find anything on WOS
... well as the above mentioned Upper RAM modules:-
[url=" ... details/ZX-Spectrum-4116-(lower-RAM)-replacement-module.-2741"]https:// ... 67363-An-alternative-Spectrum-lower-RAM-replacement"]amibay.com/showthread. ... 2) and 3) have not yet been discussed. -
The Different Approaches To Upgrading the ZX Spectrum from 16K to 48K This is probably something that has been covered before . I will take a look to see if I can find anything on WOS
... already has, or does not have and which issue board ... board),
[*]Use a upper RAM replacement module (there are two ... ).
[*]Make your own upper RAM replacement equivalent to a URR ... a ZX Spectrum, ZX81 RAM packs are not compatible),
[*]On ... -
How can I fix a problematic Retroleum Smart Card. I did not do anything "WRONG " with it but I did but it on a flexible cable and this seems to have "upset" it .Since then It does not perform the …
... Upper Ram Chip 21 is causing the fault . All the chips are not ... what caused this Upper Ram IC to fail .It does not look like ... with this on the thread "Not Bored With the Boards" -
Not bored with the Boards.Going through some old tapes stored rather badly I came across an unlikely item that that I must have stored away quickly with other low grade items …
... /> This 48k spectrum has an upper Ram fault thought to be at ... to make sure you have not damaged any of the PCB ... -
Not bored with the Boards.Going through some old tapes stored rather badly I came across an unlikely item that that I must have stored away quickly with other low grade items …
... suspect . Addressing error . Upper RAM error encountered . and then " Upper RAM Mux Error?" " IC25 ... /> I am glad I did not make it worse . Any advice ... -
Dk'tronics and other similar "add on" Speccy keyboards . What can be done with them and when?. The underlying assumption I am making here is that people who have them will want to "hang on" to them and may also want to get them working . But …
... this thread) but I did not get round to testing them ... (being repaired: it needs an upper RAM chip)
2) The ... .
So I was not testing them on a DK ... so the ZX Spectrum did not have its connectors widened out ... -
Not bored with the Boards.Going through some old tapes stored rather badly I came across an unlikely item that that I must have stored away quickly with other low grade items …
... buzzing away merrily with some upper RAM errors like it had ... />
I have not yet replaced the faulty upper RAM chip . I have ... :$00 AD: $40
Upper RAM error at $FFFF
Bad ... /> Cannot proceed further both upper and lower ram is bad .
...
