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BETA Test in Progress[url]http://www.delhez.demon.nl/[/url] BETA release 13A provides a handy token key for the popular quote character. Also, performance will improve …
... -area
Allocate 8k of RAM at 8k xsby Z80 // plus ... 32k of RAM at 16k // 32k of RAM
Shadow 16k at 16k to 48k ... -
It's a trap!So I got a CPLD (not the eventual one I want to use for the ethernet project - rather, one I actually have here and now, an XC9536 in a PLCC44). And…
... , by fooling it into thinking upper RAM is being accessed. (This will ... -
sinclair zx spectrum issue 6a (again) - how to repairHi All, Is there someone who may explain what these jumpers can be used for. [url]http://forest.no-ip.org/repair/jumpers.gif[/url] <- this is from …
Hi All,
Is there someone who may explain what these jumpers can be used for.
[url]http://forest.no-ip.org/repair/jumpers.gif[/url] -
issue 4s for reapirHi All, This time I have issue 4s for repair :) Here is few screen shots and small movie after boot. [url]http://forest.no-ip.org/issue4s/[/url] I kn…
... have good voltages in lower ram
12,5,-5
ram, upper ram, cpu, rom.
And what ... -
Repairing a faulty 48K issue 2.I am investigating one of a pair of non-working issue 2 48K Spectrums that have been sitting in a cupboard untouched for quite a few years. I haven…
...
The lower RAM chips are marked ITT 4116 ... RAS signals at all RAM chips (upper and lower).
... all
the upper RAM chips, which I imagine is ... pins of all RAM chips
(upper and lower), ... WE is ~5V at all RAM chips (upper and lower).
< ... -
Faulty rubber speccy - advice neededHello all speccy hardware gurus :) Recently I moved to a new flat and after a long time have some space (and time) to dig out my old Speccy hardware…
... have faultered. This motherboard had upper ram chips socketed so I pulled ... was the same as with upper ram fitted - black paper with ... (over 2000k, as with other upper ram chips), and not below 20k ... after fitting back all the upper ram chips, the pattern on the ... -
ZX Spectrum not working... issue 4S?Hi, I've bought a "new" broken ZX Spectrum +. The idea was to put an harlequin board inside, but for the moment I'm trying to put it in working order…
... and the logic chips for upper RAM mounted in sockets.
- Lower ... get some 4116s?
- Is upper memory more resistant or it ... -
My Issue 2 spectrum"IT'S ALIVE!!!!!" - Dr Frankenstein I got my issue 2 spectrum up and running, colours and all. I borrowed socketed lower ram from my issue 3 that is…
... all. I borrowed socketed lower ram from my issue 3 that ... it can not find its upper ram. It is quite possible that ... well as it did lower ram and cpu. They are GM7164p ... -
Issue 3 board - Free to good homeI have an issue 3 board that someone could scavenge for spares or even repair if they're willing to pay the p&p. I got it off someone on Amibay in a…
... some stage most likely a RAM had bought it, taking both ... ) socketed NEC z80 and socketed upper ram. I'd rather turn this ... -
Assembly game programming on ZX how-to?Hi. I'm planning to build and release new software for the Speccy but I'm pretty lame as to handle its hardware despite a good mastery of Z80 assembl…
... ? Like drawing the "sprites" on upper RAM and "blitting" it to the ... -
Lower Memory - Why Multiple Voltages?Having spent much of the weekend working on getting my old Spectrum working, my Dad (who is visiting) and I were chatting about the schematic. Given…
... .
Given that the upper RAM in a Spectrum is of ... in the lower portion of RAM?
Surely it would ... -
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…
... and blowing all the lower ram and the regulator. So now ... fitted with Zorns excellent ram module, the upper ram is in the process ... socketed in preparation for Zorns upper ram module, a recom unit from ... -
Question about 48K DRAM refreshHi guys. Can anybody tell me how the 48K spectrum refreshes the upper ram. RAS only? CAS before RAS? I've got a bunch of 41256 DRAM that i would lik…
... the 48K spectrum refreshes the upper ram. RAS only? CAS before RAS ... -
I've had better nights...So I got a broken issue 2 today, case in good nick but the diags board showing multiple failures in both lower/upper RAM. Never mind, good as a spare…
... multiple failures in both lower/upper RAM. Never mind, good as a ... failures in previously good lower RAM and a pattern exhibiting a ... I can perform on lower RAM in the future out of ... -
Power consumption improvementsHi all, Having just received lower and upper RAM replacement modules from Zorn, I thought I'd perform some current draw measurements to see how much…
... /> Having just received lower and upper RAM replacement modules from Zorn, I ... type. Next the RAM:
Recom + Lower RAM module: 260mA
Recom + Both RAM modules: 210mA
Calling people with Diagboards.....and who have toastracks or grey +2's with all socketed memory :) I'm finishing off modifications to the Diagboard firmware to expand its testing c…
... 's sample output when IC16 (upper RAM) is removed:
[IMG ... when IC6 and IC8 (lower RAM) are removed:
[IMG ... output to screen the specific upper RAM IC locations that have failed ...Using VAC PSU in DC deviceHaving fixed the dead Issue 3B, I began to wonder about the PSU that came with it. It was pretty obvious what had killed the poor Spectrum as the PSU…
... TR5, probably dead lower and upper RAM, partially dead ULA and lifted ...Wanted: ZX Spectrum rubber or + casesHi all See, now I have a lonely issue 1 board that is naked and need of a case to live in now that I have repaired it (well the main PCB is repaired…
... a go at the 32k "upper" RAM plug in board). It found ...Issue 2 Spectrum - Black screenHi I have an issue 2 spectrum which I'm having some issues with. I bought it on ebay so have no idea of the history or how it came to be broken. Whe…
... appear that this is an upper RAM fault.
As ... to get the corresponding upper RAM location and sure enough ... I replaced the offending upper RAM chip but it made ... some of the lower RAM chips about to different ... the same to the upper RAM and the fault stayed ...No text at startupGreetings from Norway all Spectrum enthusiasts. I hope someone can help me with this. When I power up my Spectrum 48k (issue 3b) I get a white border…
... screen. I have replaced all upper RAM chips and replaced capacitors without ...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…
... fail then
Lower ram tested on 200Kohm range
Upper ram socketed
Any comments ...Bizarre ZX Spectrum faults (also possibly relevant to Spectranet compatibility problems).I'm attempting to repair an issue 4A 48K ZX Spectrum and am encountering some very strange problems. For my own records I've given this computer the …
... capacitance: no faults apparent and upper RAM RAS/CAS times appear correct ... .
Following changing the upper RAM from the original OKI ICs ... , only when the original OKI upper RAM is fitted.
- Spectranet: Computer ...Issue 4A, tests complete fine but get odd crashing problemHi all, I've got an issue 4A which has had all of its lower RAM replaced, TR4, TR5 as well as its CPU. It originally had quite high voltages (20-3…
... line and some very questionable RAM. TR4 and TR5 were ... replaced and with new RAM it appeared a lot ... 've tried swapping the RAM chips around and have ... difference. The voltages on the RAM appears fine.
upper RAM or the logic chips ...What are the chances?Hi all, I've picked up an issue 3B, fairly clean board, no mods, wasn't starting correctly so I tried Brendan's diagnostic ROM and got this: [i…
... [/img]
Total lower RAM failure? Before I start pulling all ... the RAM out, is it possible that ...bizarre error on a grey ZX Spectrum+2 - the long search for a small problemHi, I got a ZX Spectrum+2 that worked a bit but crashed while loading or running 128k games. I installed a 128k-test-ROM that told me about RAM fa…
... -ROM that told me about RAM failure at page 3. I desoldered ... 8 RAM chips that included page 3 as the failure seems ... to be located in several RAM cells not ... I removed the second 8 RAM chips - to save time I ...ZX Spectrum 48k issuesHi all! A couple of days ago I bought my first 48k Speccy off ebay (I already own a beautiful QL expanded with QubIDE interface and 640k ram). It was…
... with QubIDE interface and 640k ram). It was advertised as "it ... , power connector) and the socketed upper ram, fully recapped it, added composite ... reports faulty reads from ram (removing the upper ram does not resolve).
48k spectrum problems at bootHey guys so my 48k Specfy, Issue 3B is having some issues. They're not entirely consistent but the majority of the time (95%) it presents itself as m…
+3 memory repair- which ICHi there, I'm trying to repair an old +3 and have bought a Retroleum SMART card. The diagnostic rom test says that the upper ram is faulty and give…
... rom test says that the upper ram is faulty and gives the ... the last address in the upper ram. I therefore don't know ...48k Issue 6a Very sick indeed.Hi Guys. I have a 48k Issue 6a board that shows a white screen with grey border. The white screen has three black squares spaced equally on the le…
... 7805 regulator, socketed lower and upper RAM, switched ram from another board, without ... coil.
My lower RAM voltages are -5V = -029.5mV ...Z80onDSK now compatible with +3e with ZXMMC or similarJust updated my utility to work on Spectrums equipped with +3e ROMs and IDE storage. I've tested this with ZXMMC at the moment but don't think there …
... 16k. Clears top 2 memory banks to remove erroneous data in upper ...
║ memory for 16k games. Helps reduce ... /> ║ or PC are in upper mem (>0x7fff) utility will ... patched in. Note this causes upper mem to be
║ ...
