[1] The Sinclair calculators were successful because they were far cheaper than the competition; however, their design led to slow and less accurate computations of transcendental functions (maximum three decimal places of accuracy).

[4] An extensive manual explained how to calculate functions such as trigonometry, nth root extraction and compound interest on the device.

Due to the use of contacts made of nickel coated with tin, rather than gold, an oxide layer would be smeared across the insulating barrier after repeatedly using the switch.

[7] On later scientific variants the power draw for the display required a larger PP3 battery, creating a bulge in the lower rear casing of the appliance.

[7] The Programmable came with a program library consisting of four books, covering general functions, finance & statistics, mathematics, physics & engineering and electronics.