Flakey HP 70: post modified as RAM Chip identified.

[Harald]

(10-22-2015 06:52 AM)Geoff Quickfall Wrote:  Aha, that's the table I am using!

Tomorrow I will harvest a RAM from a 45 and see if that fixes the 70.

By the way, the stack as well as the 4 basic functions all work, it is jus the higher registers that return a 0 no matter the input.

Thanks Didier.

Geoff

Does sound very much like a RAM problem.
It could be the ROM that partially works and instructions related to the financial functions don't work, but that seems rather unlikely.

I nearly bought a 70 the other day - but couldn't justify spending that much money and ended up loosing the auction...