HP-33E How many chips?


I've just bought a 33E. It does not work at the moment and I have no history so I don't know if its been messed about with before. Having removed the back, I've noticed that the bottom-most 8 pin chip is missing. Is this normal or has it been removed or swapped around. The only picture of this calc I could find in the museum showed a missing chip at the top position. Anybody help?

Chris S.


In the Spice models that I've seen, there are no missing chips. Chances are your machine was cannibalized.



Thanks for the info.

Chris S.



It appears that I lied to you... last night, I disassembled an HP-33E and guess what! Only two of the little chips in there and it works!

Apparently, in later models (this is a later, US model as opposed to the others I saw that were made in Singapore) one of the chips was eliminated and another replaced with a different model (obviously taking over the function of two chips.)



I've worked on four of the 33Es. One of them did not have the top 8 pin IC installed but it worked fine. It had a 2014 data code, the others had older date codes. The second IC had PN IMA 1204 in the one without the IC. The others had PN IMAI 0004. It looks like they may have combined IC 1 and IC 2 in the later models.

Joe Rigdon

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