HP-91 Simulator

[Dieter]

(02-09-2017 05:46 AM)teenix Wrote:  I did not have access to the microcode for this calculator, so I looked through the various classic models and the HP-55 had the closest match for the functions required for the HP-91.

There was a major change in the internal routines, starting in 1976 with the HP67/97 and 91. At that time HP switched to the now common 13-digit internal precision, among other improvements e.g. in the trig routines. This significantly improved accuracy.

Details can be found in the November 1976 issue of HP Journal, p. 16 ("The New Accuracy: Making 2³=8").

(02-09-2017 05:46 AM)teenix Wrote:  Therefore, the results should be exactly like the HP-91 would have produced.

Sure ?-) Try the examples listed in the mentioned article.
What do you get for tan(pi) in radians mode? Is it 0 or 4,1 E–10 ?

Dieter