Display is 8 digits, green vacuum fluorescent.
4-function, %, memory, square root, square.
3v (2x AA battery).
Calculator integrated circuit: National Semiconductor MM57134ENW/M.
160 x 94 x 28 mm (6.3 x 3.7 x 1.1 ins).
Launched early 1978.
"Assembled in Hong Kong
Designed in Great Britain"
Circuit boards are marked "Radofin" - See Radofin under British Calculators.
Price £17.95 (about US$36).
The silver paint on the President models is notorious for wearing off, as in the example photographed above.
This was one of the last Sinclair models, and ironically, since the company was famous for the incredibly small size of its first model, the Executive, is also the largest, see the photograph below. The operating manual explains
this by saying "The President is primarily intended for on-desk use."
This is also the only Sinclair calculator model not made in England. By now the calculator market was very competitive and Sinclair made use of the cheaper manufacturing costs in Hong Kong for what was by then a basic calculator. The circuit boards are marked Radofin, a British based company which also had a subsidiary in Hong Kong.
The President series were some of the last Sinclair models and are rather large, see the photograph below. This is ironic considering that Sinclair was famous for its first model, the Executive, which was very small. The operating manual explains this by saying "The President is primarily intended for on-desk use."
The President models are also the only Sinclair calculator models not made in England. By now the calculator market was very competitive and Sinclair made use of the cheaper manufacturing costs in Hong Kong.
Showing the large size of this model, which was designed primarily for desk top use.
With the back removed. Note the "Radofin" name on the keyboard circuit board.
Radofin was a company based in both London and Hong Kong which also sold calculators under its own name.
The main circuit board of calculator. Prominent are the vacuum fluorescent display (VFD) and the National Semiconductor calculator chip.
This board is also marked "Radofin" on the back.
Vintage British Calculators
© Text & photographs copyright Nigel Tout 2000-2023 except where noted otherwise.