Which calculators had no known bugs?

[Sylvain Cote]

(11-13-2017 01:33 PM)PANAMATIK Wrote:  If you enter all 98 program steps numbers and run, the program can't be interrupted. You have to switch off the calculator.

Bernhard,
I do not see this behaviour on my HP-29C (sn: 1908S22721)
My test program consist of 98 lines of + instructions (key code: 51)
I fill up the stack with 1, then run the program.
The adding program run indefinitely because of the loop around, but I can stop and restart its execution at will.
Sylvain