the calculator home page

Sinclair Cambridge Programmable

The Sinclair Cambridge Programmable is a programmable calculator with 8 digits precision and algebraic logic. It has 51 functions, 19 keys and an LED (light-emitting diode) display, typical of calculators of this era. The power source is PP3 9V.

This fascinating and very early programmable calculator came with a huge set of four manuals containing programs to solve various mathematical financial and engineering problems.

It was obviously quite a challenge to create a programmable calculator with so few keys. Power was also a problem - a higher voltage than anticipated was needed to achieve sufficient speed, and so a 9V battery was used to replace the AAA batteries used in other calculators in the Cambridge series. Unfortunately the only way to accommodate this was with a special battery cover with a bulge to accomodate the larger battery. As a result the calculator does not sit squarely on the desk but topples.​

Facts at a glance:

Type Programmable
Functions 51
Keys 19
Precision 8
Logic Algebraic
Display type LED
Display size
Length 112 mm
Width 51 mm
Thickness 25 mm
Weight 90 g
Power Source PP3 9V
Original price $35.00
Est. current value $75.00
Year introduced 1974
Year discontinued 1978

See other calculators manufactured by Sinclair.