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
History of science and technology in Japan fluorescent display (VFD) and rechargeable NiCad batteries. The EL-8 was the first battery-powered handheld calculator. The concept of a single-chip calculator was conceived by Sharp engineer Tadashi Sasaki in 1968. The first truly pocket-sized electronic calculator was the Busicom LE-120A "HANDY", the first single-chip calculator to be built, released in February 1971. The Busicom 141-PF desktop calculator, released in March 1971, was the first computing machine to use a microprocessor, the 4-bit Intel 4004 (co-designed by Busicom's Masatoshi Shima). In 1971, Tadashi Sasaki began research on the use of LCD displays for calculators at Sharp Corporation. In 1973, Sharp commercially