From: Ethan Dicks (ethan_dicks_at_yahoo.com)
Date: 2002-04-16 17:56:25
--- Klaus Seiner <kseiner@edu.uni-klu.ac.at> wrote: > Hello! > > I have a dead PET 2001 (first version with 6550´er RAMS). On startup it > shows just garbage chars on the screen. I suppose the ROMS are dead. Not necessarily. I've seen dirty sockets or loose chips cause all sorts of problems. I had an old 8K static RAM PET that would not work unless there was a cardboard shim under the middle of the motherboard. Something about board sag and loose socket contacts. You might pull each ROM and RAM chip, inspect for tarnish (if they are silver-plated pins, they will be black after this many years) if clean, just re-insert. If not, I'm not sure the best way to remove visible silver oxidation from CMOS SRAMs without generating static. > Can anyone (or has anyone) tell me how to replace the original ROMS with > EPROMS? I guess socket adapters are needed to. And which kind of Eprom > to use? Personally, if I were going to replace the ROMs, I'd consider replacing the sockets, too, with machined (turned) pin sockets, or making an external ROM board for the edge connector (also with machined pins). You could put all of the ROM code in a single chip. -ethan ===== Visit "The Seventh Continent" http://penguincentral.com/penguincentral.html __________________________________________________ Do You Yahoo!? Yahoo! Tax Center - online filing with TurboTax http://taxes.yahoo.com/ Message was sent through the cbm-hackers mailing list
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