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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 ...repaired a 48K, yay :)I just managed to repair one 48K. After socketing all eight lower RAM chips (hard work!) and replacing few of them, it showed the familiar "Sinclair …
[QUOTE=orange;504687]question: does that mean all lower RAM is now OK? (if so, I could use it to test chips)[/quote]
Yes. Each chip is in charge of one bit of data.Speccy 128 Shadow screen.How much is the shadow screen used in 128k commercial software? I ask because I am looking at putting 128k of memory in the 48k setup I have been bu…
... seperate ram for the ULA ram and the non-ULA ram, ... reading the non-ULA ram (So i dont care ... two pages the ULA ram is presenting), which means ... is the Refresh of the lower ram, which i will probably ... currently using with a static ram chip instead.
How the spectrum generates the video from ramHi everyon, I know that most people here allready know this but i think i found out how the spectrum acctually dispalys stuff and why the LD x, (HL)…
... the ULA reads the video ram in a real spectrum by ... or writing to the lower 16k of ram in a real spectrum ... is the master of the lower ram and even takes care of ...How the spectrum generates the video from ramHi everyon, I know that most people here allready know this but i think i found out how the spectrum acctually dispalys stuff and why the LD x, (HL)…
... the ULA reads the video ram in a real spectrum by ... some other area than the lower 16K, there is no conflict ... is the master of the lower ram and even takes care of ...Fully integrated ZX+Hi, I just want to show some inspiration for integration HW to ZX+ case ;-) - ZX48 issue 3 board, without all parts regarding video generating (pa…
... tell the difference between a lower Ram read by the CPU (Always ... page 5) and a lower ram read by the ULA (Page ... 7 depending on the shadow ram pin), so i havent been ...Some 48k+ packages for saleSoon! Rwap is sending over a few membranes for 48k+ machines, so far, got two fully functional (and looking good!), soon as the membranes are in the…
... an interface 2 to detect lower ram probs.. if horace on cart ...2 48K speccys dead..Hey guys! I've got two of our rubbery friends with me that need some help. They've been like this for some time, but I would like to try and fix th…
... /> Indeed check voltages on the lower RAM chips - the above looks OK ... keyclick, ULA (most likely) or RAM / ROM / Z80 fault.
2 48K speccys dead..Hey guys! I've got two of our rubbery friends with me that need some help. They've been like this for some time, but I would like to try and fix th…
... ]Indeed check voltages on the lower RAM chips - the above looks OK ... keyclick, ULA (most likely) or RAM / ROM / Z80 fault.[/QUOTE]
2 48K speccys dead..Hey guys! I've got two of our rubbery friends with me that need some help. They've been like this for some time, but I would like to try and fix th…
... and replaced 7805. On the lower RAM I'm getting -5V/+10V ...Hi everybody! Need help trying to rescue a ZX 48K...Hi, since this is my first post, a bit of info about me: I'm an Italian guy, now living in Poland (Warsaw), informatics and electronic geek since…
... hot.
The lower 16K RAM is more exposed to failure ... chance that some of the lower RAM is defective.
Check if ... any of the RAM-chips are hotter than the ... just have to replace the RAM and see if it helps ...Amperage drastic reduction in a rubber 48KWell, I am now with the approach of a drastic reduction ZXSpectrum amperage. As a first step would change the Z80 processor for other (Z80C). Unfortu…
... got rid of the crappy lower ram chips.[/QUOTE]
I ... fix removing the 8 integrated lower memory, IC25 & 26 and ...Amperage drastic reduction in a rubber 48KWell, I am now with the approach of a drastic reduction ZXSpectrum amperage. As a first step would change the Z80 processor for other (Z80C). Unfortu…
... got rid of the crappy lower ram chips.[/QUOTE]
No ...ZX Spectrum 48k issue 3b power problem?Hi :) I was lucky enough to find a couple of ZX Spectrums at a car boot sale yesterday. I spent the evening fiddling about with one (issue 2) and t…
... problem ( very strange) maybe a lower ram problem. The last spectrum I ... . The problem was a faultly ram chip 4116.
Bye ...ZX Spectrum 48k issue 3b power problem?Hi :) I was lucky enough to find a couple of ZX Spectrums at a car boot sale yesterday. I spent the evening fiddling about with one (issue 2) and t…
... problem ( very strange) maybe a lower ram problem. The last spectrum I ... . The problem was a faultly ram chip 4116.
Bye ... do I check whether the ram 4116 chips are working okay ...Spectrums with gold RAM chips?Hey people, This is a first for me: [img]http://www.mutant-caterpillar.co.uk/ian_stuff/blingspeccy.jpg[/img] Is it normal to have gold RAM chips? …
I have one of such spectrums too, but lower RAM is defect.. Looks pretty. But never seen them in Issue 3 onward boards.Spectrum+ fault - lines on boot screen, freezesThe ZX Spectrum+ I bought in the car boot has a fault. When you boot it, it's displaying the Copyright screen, but each character position has a vert…
... the machine powered up, the lower RAM (4116 memory) can become faulty ...Spectrum+ fault - lines on boot screen, freezesThe ZX Spectrum+ I bought in the car boot has a fault. When you boot it, it's displaying the Copyright screen, but each character position has a vert…
... the machine powered up, the lower RAM (4116 memory) can become faulty ...rubber key Spectrum 48k problem :(when i plug the spectrum in all i get is a black screen with a red border and sometimes flashing blocks. the spectrum worked until about 20 mins ago…
... ] the voltages on the 16K lower RAM. You should get pin 1 ... you have a dodgy 16K RAM chip. If you have access ... to have to keep remove lower RAM chips until you find the ...
