NOP on HP-41C

[Werner]

(11-22-2020 12:50 AM)Thomas Okken Wrote:  Hmm. I have been thinking about how to add a NOP instruction to Free42 in a backward-compatible manner, and I had completely forgotten about TEXT 0. It fits the bill perfectly! Nice, I'll go ahead and use that, then.

a SKIP instruction would also be nice, but there is no 1-byte equivalent that will always work ;-)

You might wonder where a SKIP instruction would be useful. If you have two tests, A (eg. X=Y?) and B (eg FS? 25), how would you implement:

1. if A or B then x; y; end :

01 ^A
02 B
03 SKIP
04 GTO 00
05 x
06 y
07 LBL 00

2. if A and B then x; end

01 A
02 ^B
03 SKIP
04 x

I've always managed to find 1-byte always-false-fillers to use as skip, though ;-)
Cheers, Werner