Hi all,
my HP 54200A left me. It dumps lots of &&&&& on the screen, no beep, no keyboard actions, no obvious hardware damage.
I suppose that the contents of the EPROMs have partially disappeared after 23 yrs. Lots of FFs between binary and text code, quite unusual for expensive EPROMs anyway.
Does anybody own a functional 54200A and is willing to read those EPROMs and mail me the content?
Any help is much appreciated.
Thanks,
Andy
If you have a universal programmer, it may be worth trying to read them with a lower Vcc - if bits are marginal, this may be enough to get the data out.
I gave it a try and went down to Vcc=3.8V step by step. Between 4V and
5V read checksum is stable, below 4.0V I get random checksums. I think I won't be able to recover the data from the old EPROMs...Thank you Mike and best regards, Andy
Andy - I send you the binary images to your email address... Good Luck. Jim
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