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CMT71-64E HP-71b eprom module questions
06-05-2019, 02:19 PM
Post: #5
RE: CMT71-64E HP-71b eprom module questions
I did what you proposed, open the CMT 64K Module, desolder the 27C512 in PLCC 32, tried to read/program in a PLCC 32 Socket,
but that failed due to contact issues.
So I soldered it with wires to a DIL socket. I could read the EEprom,
Erase it, but re-programming failed, as did the second one. Since I could not easily get 27C512 chips, I bought a couple of
T1-74 Memory Modules...., and used their Atmel 27C512, and could program them. Soldered a PLCC 32 socket on the CMT module, put the Atmel in it,
and it did work !! The second one I did I continued to have contact problems,
so I soldered the Atmel direct to the CMT, it did work.
After some time, it failed, as did the one in the socket, if I do a CAT on the port, the Display turns blank.
In short, too much work for no result.

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RE: CMT71-64E HP-71b eprom module questions - RamLab - 06-05-2019 02:19 PM

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