APF MARK 55

APF MARK 55
Image: wass.net used with permission
The APF MARK 55 is a scientific calculator with 12 digits precision and RPN (reverse polish notation) logic. It has 45 functions, 30 keys, and an LED (light-emitting diode) display, typical of calculators of this era. The power source is 3xAA sealed. Note: Similar to HP calculators.

Facts at a glance:

Feature Value
Type: Scientific
Functions: 45
Keys: 30
Precision: 12
Logic: RPN
Display type: LED
Length: 159mm
Width: 76mm
Power Source: 3xAA sealed
Year introduced: 1977

See other calculators by APF