British Calculators

Home > British Calculators > Sinclair

Sinclair Executive Memory

Casing style 1

Casing style 2

Casing style 3

Sinclair Executive Memory
Sinclair Executive Memory
Sinclair Executive Memory

Sinclair Executive Memory

Similar to the Sinclair Executive above, but also has a memory.

Display is 8 digits, red LED.

4-function, memory.

5.4v (4x mercury button cells).

Main integrated circuit: TI TMS0132NC.

56 mm x 138 mm x 9 mm (2.2" x 5.5" x 0.4").

Introduced 1973.

Made in England.

Is found in at least three styles of casing, as shown above.

The incredibly small thickness for this stage in calculator development was attained by using button cells as the power source.
The keypad uses a very thin plastic membrane moulding to keep the thickness down.  The actual keys are the tiny buttons in the centre of each pad area.

This model is found in at least three casing styles, as shown above.  Casing style 1 (white and black) version is more common than the casing style 2 and casing style 3 versions.

Sinclair Executive Memory in hand
Sinclair Executive Memory side view

Side view showing how thin this machine is.

Sinclair Executive Memory circuit board

Sinclair Executive Memory circuit board and part of the casing.  Distinctive features, from top to bottom:

  • Small LED display with array of lenses, mounted towards the right side of the circuit board.  Has two SN75492N LED display digit driver chips below.
  • TMS0132NC chip (here date coded 1973, week 40).
  • Contacts for four button cells.
in case

Sinclair Executive Memory in presentation case, with soft pouch and instructions.

Black version

Black Sinclair Executive Memory

Frank Fröhn has kindly provided this photograph of an all-black Executive Memory.  The only marking on it is the logo, which appears to be that of CBS (Columbia Broadcasting System), so it was probably supplied as a promotional item.

Vintage Calculators

© Text & photographs copyright Nigel Tout   2000-2019  except where noted otherwise.