The Cambridge was as much of a marvel as the first Sinclair calculators were.  It measured only 4.3 x 2.0 x 0.7 inches and weighed only 3.5 ounces.  It featured fully-floating decimal point, algebraic logic, a constant on all four functions and a bright 8-digit display through the trademark purple filter.

It was sold in both kit and fully built form.  It was expensive when it first sold but its price dropped dramatically as the market was flooded by cheap eastern machines.  In late 1974 it was only £21.55 for a built unit and this price had fallen to below £15 less than twelve months later.

This model was soon joined by the Cambridge memory and other more sophisticated units were to come (see the other models on this site).

This is a fairly difficult calculator to find and is certainly sought after by collectors.  You would be very lucky indeed to come across one at a boot sale.  If you do see one then buy it!  Complete kits in their original packing are almost unheard of.