Curiosity about HP-65 Standard Pac

[rprosperi]

(01-09-2019 11:08 PM)Dieter Wrote:  You may take a look this thread (in the old HPmuseum forum). The letters A or B seem to indicate different revisions of the same program, maybe bugfixes.

Please also take a look at the last message in the linked thread. According to that post HP indeed changed the first program of the HP65 Standard Pac. Looking at your picture you seem to own both versions of the first program: the calendar program as well as the investment program.

On the other hand the letter A or B usually seems to refer to different versions of the (basically) same program. This seems to be the case for your SD14 program: you got both the original program and the revised version of the solver program.

There are several 'non-standard' things about the HP-65 cards, when using later machine card sets as the 'standard'. There were indeed several examples of different programs with the same program number, etc.

As the HP-65 was the first calculator with mag cards, I suppose there was no standard behavior to follow, but no doubt after having customer support issues, manual update issues, etc. they sorted it out, as I don't believe this was repeated with the HP-67/97. The appended "A", "B", "C" indeed were revisions of the original program, sometimes with minor changes to the program behavior/results; one well-known example is the Diagnostic program which came in SD-15A, SD-15B and SD-15C versions, with the last one producing different results from A and B (possibly due to changed firmware needing different tests?).