TI59 Diagnostic forensics

[pinkman]

(07-27-2020 11:18 AM)Maximilian Hohmann Wrote:  Hello!

Very interesting. My Ti59 (bought new in 1978...) did not come with that card.

What I fail to understand however is why such a complicated calculation must be done to check if the calculator is working. It does not have a seperate floating point unit as far as I know, just a single CPU. So if it is able to come up with the correct result for "1+1" it should be good for everything else, shouldn't it?

Regards
Max

As said above, it seems to test more than just the CPU health.
But if I was mandated to create a test program for a calculator during the 70´s I for sure would try to run all the parts of the ROM or the CPU, not only “CPU OK, ROM OK”.
And this one seems to be very clever (the 8s, the memory full of NOP codes, ...).