Sterling Currency Calculators
Contex
Contex S/1
This is a low-cost, plastic, Abreviated-Keyboard, £sd adding machine. The mechanism is derived from that of the Comptometer, but with the keyboard and display reversed.
It has four £ decades, a single tens of shillings key, shillings, pence, and ¼ & ½ pence.
The machine illustrated above is displaying a total of £1,234 15s 11¼d.
To enter a number above 5 the operator has to press two keys in succession in that column which add up to the number required.
To enter 11 in the Pence column the operator has to press 3 keys !!, eg. (5)+(5)+(1).
203 mm x 233 mm x 70 mm. (8" x 9" x 3").
Introduced in the early 1950s it cost £18 12s 6d Sterling (about US$50).
Models advertised were:
- S/1 - Capacity £99,999 19s 11¾d (illustrated above).
- S/2 - Capacity £999,999 19s 11 (as illustrated above but without the ¼d and ½d keys but with an extra column of £ keys on the left.
- Decimal - Capacity 999,999,999.
Made in Denmark, distributed in UK. by Office Machinery Ltd. (Omal).
Looking underneath with the bottom cover removed shows that the calculator mechanism is cheaply made, largely from components stamped out of phenolic sheet.
Advertisement for the Contex from Office Magazine, 1955.
Sterling Calculators
Vintage Calculators
Text & photographs copyright, except where stated otherwise, © Nigel Tout 2000-2024.