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HP-71B to sacrifice in the name of SCIENCE!
03-10-2024, 12:28 AM
Post: #3
RE: HP-71B to sacrifice in the name of SCIENCE!
I just discovered that my 71B with S/N prefix 2635A (metal back, 1BBBB, presumed 1LF2 CPU) actually works from an 82059B AC adapter. It fails to work from alkalines. There's no sign of battery contact corrosion. Since it's functional, I suppose I should take it apart to diagnose and repair it, rather than part it out. So I'll still be on the lookout for a broken early 71B to sacrifice for 1LF2 chip decap and photomicrograph.

In the mean time, this means that I'll be able to do some testing of the differences (or lack thereof) between the 1LF2 and 1LK7. I expect that the undocumented behavior of BCD arithmetic on non-BCD values is probably identical. It will be interesting to determine what length the 1LF2 thinks the level 1 opcodes are, and what (if any) affect they have on registers.
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RE: HP-71B to sacrifice in the name of SCIENCE! - brouhaha - 03-10-2024 12:28 AM



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