have you ever withnessed calculators not working anymore due to corrupted memory?

[edryer]

Quote:Hi, I had a Casio FX-602P where one memory failed after 10 years. When I put 3 in M06 and then recall M06 it returned zero. So one bit failing. Made a control program to check the rest, but only M06 had problem.

Interesting, although this is an old thread also I experienced this with an FX-602P, storing in M10 (all other of the 89 memories OK) I get corrupt results, that is I store a number it will have the 8th digit corrupt, if it is a shorter integer it will add that "digit" as some (non-random) bit.

Example "123 M IN 10" (store to memory 10)
And then when "MR 10" I get 123.0008, also with other numbers I also get bit corruption (on the the eight place only) these are reflected if I use the number resulting in incorrect results.

Later Casio's (such as the 1986? FX-3900P) I have never seen this issue - in fact the later calculators in the "P" series I think never suffered from memory issues, nor did the contemporary (limited likely to one memory) (1979) FX-80, FX-81 basic scientifics... nor I believe the FX-180P (1981?).

The Memory used in the FX-501/502/601/602P likely changed* in the next generation FX "P" machines emerging around 1984-1985.

Still.. usable...with that quirk, but it is an interesting machine, has a good programming model but the functions are limited, esp the stats stuff as a few years later Casio went way overboard on stats functions shifted on the numeric keys.

Casio's are very interesting... they have kept a uniform naming sequence generally for forty odd years, and even a mid 70's scientific can be seen today in the design of the FX-5800P.

Same with graphing... a 1996 model has mostly the same OS as a 2018 model... only a little has changed (such as RUN and MAT now on the same tab)... can switch between the two without thinking (9750G from 1996 to todays CG series).

*From the NEC uPD444G 1024 x 4-bit S-RAM in an SMD package used (also in the FX-702P)