Bug in the HP-41 with R/S and stack lift

[J-F Garnier]

(10-31-2020 11:47 AM)Didier Lachieze Wrote:  That's an interesting corner case, because in general I think that you would not want R/S to be neutral with regard to stack lift. When starting a program sequence with R/S I expect stack lift to be enabled, otherwise the following sequence would provide a different result if the user enters 0 or just press CLx before pressing R/S:

Code:

STOP
2
+

in the first case the result would be 0+2, in the second case it would be Y+2.

Good point, actually PROMPT is very often used to enter values followed by R/S.

On the other hand, sequences like "8 ENTER 9" were almost never used by 80's HP-41 users, who just used "8 9" (doesn't save a byte but is marginally faster) so the R/S stack lift enable effect is rare (although yes it can happen so it's good to know it).

J-F