HP-33E - Three 8 pin ICs - Which goes where?

[PANAMATIK]

(09-01-2016 11:55 AM)Harald Wrote:  The position of the ICs is not critical. They are alle wired in parallel. But the orientation has to be correct. Pin 1 has to be in the correct position. I am sure you can find the orientation somewhere on the web.

If it is a E model like 33E you are right. If it is a C model like 33C, then the RAM chip must be placed in the first/upper position, because only this place gets battery power when swithed off to retain Continuous Memory data.

In Gersons case, there is used a single combined ROM/RAM chip.

Bernhard