Calculator calculator marketed to the Real Estate industry with preprogrammed functions to simplify the process of calculating payments and future values. In 1985, CI launched a calculator for the construction industry called the Construction Master which came preprogrammed with common construction calculations (such as angles, stairs, roofing math, pitch, rise, run, and feet-inch fraction conversions). This would be the first in a line of construction related calculators. The first desktop "programmable calculators" were produced in the mid-1960s by Mathatronics and Casio (AL-1000). These machines were very heavy and costly. The first programmable pocket calculator was the HP-65, in 1974; it had
Sinclair Wrist Calculator Sinclair Wrist Calculator The Sinclair Wrist Calculator was a wrist-worn calculator produced by Sinclair Instrument and introduced in 1977. The Wrist Calculator was launched in February 1977 by Sinclair Instrument, a company established in parallel to Sinclair Radionics when the latter started to encounter financial difficulties. It was only available as a mail-order kit, and cost around . Despite the difficulty in assembling the kit due to the small size of the parts and their variability in specification, 10,000 were sold around the world. 20,000 were exported to the United States, but most went unsold and were returned to Sinclair.