the calculator home page

Hewlett-Packard HP 91 Topcat FELIX

The Hewlett-Packard HP 91 Topcat FELIX is a scientific calculator with 12 digits precision and RPN (reverse polish notation) logic. It has 56 functions, 42 keys and an LED (light-emitting diode) display, typical of calculators of this era. The power source is 4x1.2V NiCd battery pack.

Facts at a glance:

Type Scientific
Functions 56
Keys 42
Precision 12
Logic RPN
Display type LED
Display size
Printer Y
Length 202 mm
Width 228 mm
Thickness 64 mm
Weight 1134 g
Power Source 4x1.2V NiCd battery pack
Original price unknown
Est. current value unknown
Year introduced 1976
Year discontinued 1979

See other calculators manufactured by Hewlett-Packard.