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Remove +12 Volt itemsWhich items can be removed on a ZX48K issue 4b PCB if I don't need the +12 Volt? Micky
... the PCB? What 32 K RAM have you used?[/QUOTE]No ... 8 4164 rams for the lower ram instead 8 4116 rams.
The 34k ram is a NEC D43256BCZ-70LL ... . It is for the upper ram.
Micky -
Remove +12 Volt itemsWhich items can be removed on a ZX48K issue 4b PCB if I don't need the +12 Volt? Micky
... 3 ICs which replace the lower RAM? -
Remove +12 Volt itemsWhich items can be removed on a ZX48K issue 4b PCB if I don't need the +12 Volt? Micky
... 3 ICs which replace the lower RAM?[/QUOTE]
Ehm... no. Not ... replacement for the Speccy's lower RAM too).
Before that ... , maybe they work as Spectrum lower RAM too? And: anyone tried 16K ... old 4116's (and upper RAM?) with modern IC's, you ... -
Broken speccys on ebayI often see broken speccys on ebay,the usual listings of no display on pic etc,i know could be opening a can of worms when buying one,so can [B]some[…
... 's what I found..
lower ram issues, no biggy to fix ... with a cart.. showed the lower ram was bust in 1... thats ... a cart will bypass the lower ram, well first bit..
Yeeeees finally got one!If anyone wants to make me an offer for the ultimate games pm me. I'm not that bothered by them tbh. [URL="http://www.youtube.com/watch?v=mVgYKMTqL…
... :)
as for the Ram turbo.. the interface 2 clone ... :) ) ya know it's the lower ram that's f'd.. :) if ...damaged spectrum+ (blinking squares)Hi, Sorry for my poor english, but I couldn't find on family forums any remedy for my hardware problem with my first speccy in my life :) I've bought…
... ... I'd be doubting between lower RAM chip(s), Z80, or perhaps ... Spectrum I'd just unsolder lower RAM IC's + Z80 now, test ...Hypothetically....If you were putting together a "Spectrum +4" what presently available hardware would you include. My criteria would be total comparability (or as ne…
... Spectrum not?
RAMCSL switches lower RAM off (16384-32767)
RAMCSH1 ... switches first part of RAM off (32768-49151)
RAMCSH2 ... switches second part of RAM off (49152-65535)
With ...Hypothetically....If you were putting together a "Spectrum +4" what presently available hardware would you include. My criteria would be total comparability (or as ne…
... Spectrum not?
RAMCSL switches lower RAM off (16384-32767)
... RAMCSH1 switches first part of RAM off (32768-49151)
... RAMCSH2 switches second part of RAM off (49152-65535)
... is rare memory. Static ram with battery backup is better ...RGB to VGA convertor for ZX128/+2/+2A/+3David Luftner release source code (VHDL) of SCANDOUBLER for ZX128/ZX128+2/+2A/+3: [url]http://velesoft.speccy.cz/other/scandoubler-for-zx128_fixed_by…
... required, something needs to refresh lower RAM).
The main issue ...I Just Listed some games on eBay[URL="http://shop.ebay.co.uk/shineyflower/m.html?_nkw=&_armrs=1&_from=&_ipg=&_trksid=p4340"]I've just listed some games on eBay, and a couple of Larg…
hairy, did ya try em with an interface 2 and a cart? just a thought.. thats how I knew the lower ram on 1 machine was knackered :)I Just Listed some games on eBay[URL="http://shop.ebay.co.uk/shineyflower/m.html?_nkw=&_armrs=1&_from=&_ipg=&_trksid=p4340"]I've just listed some games on eBay, and a couple of Larg…
... .. thats how I knew the lower ram on 1 machine was knackered ...Speccy repairs?I've finally got round to testing all the various Spectrums that I seem to have accumulated over the years and discovered that "my" two machines (i.e…
... or lower RAM is bad, most of the time it's lower RAM that ... />
Again, most likely bad RAM.
[quote]
[*] ... .
With suspect bad lower RAM you also need to check ... , then it actually kills the lower memory chips, the TMS4116 data ...Spectrum lost upper memoryHi again, I have a Rubber key Spectrum(issue 4S) which lost it's whole upper memory. It's worked okay, but i forgot it on over last night. My son wa…
... />
the heat on the lower ram is how a friend said ...The Sadness of my Decaying Speccies.I've been avidly collecting ZX Spectrums since the late 90's and whilst at the time of the late 90's and early millennium my Spectrums and associated…
9 times out of 10, RAM problems are with lower RAM (the 4116 chips ... more fragile than the upper RAM. Usually it's just one ... edge connector to test the RAM and tell which chip is ... bad.
4116 RAM was pretty much obsolete in ...The Sadness of my Decaying Speccies.I've been avidly collecting ZX Spectrums since the late 90's and whilst at the time of the late 90's and early millennium my Spectrums and associated…
... times out of 10, RAM problems are with lower RAM (the 4116 chips ... more fragile than the upper RAM. Usually it's just one ... edge connector to test the RAM and tell which chip is ... bad.
4116 RAM was pretty much obsolete in ...The Sadness of my Decaying Speccies.I've been avidly collecting ZX Spectrums since the late 90's and whilst at the time of the late 90's and early millennium my Spectrums and associated…
... saying, to be problems with lower RAM.
To amplify why ... the edge connector, thus killing lower RAM and usually the switch mode ...The Sadness of my Decaying Speccies.I've been avidly collecting ZX Spectrums since the late 90's and whilst at the time of the late 90's and early millennium my Spectrums and associated…
Lower RAM (4116) replacement is [I]technically[/ ... />
Uses ordinary 32Kx8 static RAM + 2 logic IC's - all ... my own Speccy collection, most lower RAM still works, but keyboard foils ...Maybe a bargain ?Hi guys, just won this on Ebay, Fingers crossed it all works ok, I may have got a bargain, what do you think ? [url]http://cgi.ebay.co.uk/ws/eBayISA…
the problem with speccy's is well people don't test em / sold as seen..
main 2 issues that could be a problem is bad membrane or lower ram prob.. hopefully neither and both are fixable.Help with broken SpectrumHi There, Just received a ZX Spectrum computer. It's an issue 3B (48k version). When I power it up (9V centre pin -V) nothing happens. It's complete…
... do that is on the lower RAM chips (lower left corner of board ... left) = -5V
Pin 8 (lower left) = +12V
And ... to remove the upper 32K (RAM chips in middle of board ...zx spectrum +2 troubleshootingHi There I am new here and I need some advise as to where to look for issues on my zx spectrum +2 it was working fine this morning .. then while pl…
... map you have contains a lower RAM region (16K) which belongs to ... contended bank, and an upper RAM region (32K) which belongs to ... />
If the non-contended RAM is damaged, the machine can ... .
If the contended RAM is damaged, the computer hangs ...Do ULAs die?Thought I'd start this thread as people often think their ULA is dead, when it's actually the RAM or power circuits. Searching the forum in the futur…
Anybody here an ebay sniper?Been bidding on [URL="http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=220692283001&ssPageName=STRK:MEDWX:IT#ht_500wt_1156"]this[/URL] and would …
... 'll find out if the lower ram is ***ed when I plug ... if the first bit of lower ram is broke (it replaces it ...ZX48K: KILLING keyboard membrane?Hi. My friend - JAD - decided to get back from C64 to ZX Spectrum 48K after some break (that's the man who coded this program [url]http://www.pouet…
1. Likely, lower RAM and/or the internal switch ... data sheet for the 4116 RAM and test the voltages to ...I wonder how many still goingThere is always a healthy stock of 48k rubber keyed speccys on eBay. However whats the guess on the amount world wide that are still working/used? +…
... all showing symptoms of bad lower RAM - well, except the one that ...So frustratingI'd recently socketed the lower 16k only to find the upper 32k also had issues. While removing 4 of the chips I've managed to break two tracks. The c…
if you've ripped up tracks you can certainly replace them with thin insulated single strand wire. I tore up an address line doing exactly the same as you, removing the remains of the pins of a couple of dead lower ram chips.Powering up a Speccy after long-term storage.Staying at my folks for Christmas. Feels good to be back in God's country again, even if it is -12C outside at the moment. :-o Anyway, I was plannin…
... could damage the, yet fragile, lower RAM chips.
Therefore, it ... : your computer could be damaging RAM chips as time happens, if ... (if not already) to the lower RAM chips.
- Try to be ... lucky again: one or some lower RAM chips are gone.broken 48K, strange screenwell I finally socketed all lower 16K ram chips, (8 of them in a row near corner, not those 4 in two rows) and replaced them with new ones but it did…
... works, supply voltages restored & lower RAM replaced, there isn't much ...broken 48K, strange screenwell I finally socketed all lower 16K ram chips, (8 of them in a row near corner, not those 4 in two rows) and replaced them with new ones but it did…
Lower RAM is quite(!) different from upper RAM.Testing memory/transistors etc with multimeterAnyone have a rough guide to show how to do this properly? Im using the diode setting on the multimeter to test various components, im touching the b…
... em but unless it's lower ram or ula I've not ...Testing memory/transistors etc with multimeterAnyone have a rough guide to show how to do this properly? Im using the diode setting on the multimeter to test various components, im touching the b…
... boards that ive tested the lower ram at least seems sound, went ...
