HP34C HELP

[tal]

Hello everybody,

I have an HP34C calculator, the continues memory doesn't work, I appreciate any help.

Best regards, Tal. email: td@chem.ch.huji.ac.il

[Viktor Toth]

Tal,

Exactly what does it mean that continuous memory doesn't work on your machine? Does it store/recall numbers/programs at all? Or does it work fine while the machine is on, just loses its contents when you turn the machine off and then back on again? Please provide some details.

Viktor

[tal]

Dear Viktor, The calculator works fine while the machine is on, just loses its contents when I turn the machine off and then back on again. Thanks. Tal

[Viktor Toth]

Tal,

Hmmm, that's odd. I never actually traced the circuit of an HP-34C but in other continuous memory machines, the CMOS memory is powered directly from the battery pack (with a capacitor as a backup), independent of the DC-DC converter power supply that powers the rest of the machine. So if the continuous memory receives power at all, its contents should survive power cycling.

Unless... I don't know the algorithm the HP-34C uses to verify whether the memory contents are valid, but I can imagine that if there is a failed bit in its memory, it may read the contents as invalid every time it's turned on. But I think I better stop speculating now and perhaps let others who know this machine better take over...

Viktor

[tal]

Thanks Viktor, I appreciate your effort. Regards, Tal