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
Calculator a capacity of 100 instructions, and could store and retrieve programs with a built-in magnetic card reader. Two years later the HP-25C introduced "continuous memory", i.e., programs and data were retained in CMOS memory during power-off. In 1979, HP released the first "alphanumeric", programmable, "expandable" calculator, the HP-41C. It could be expanded with random access memory (RAM, for memory) and read-only memory (ROM, for software) modules, and peripherals like bar code readers, microcassette and floppy disk drives, paper-roll thermal printers, and miscellaneous communication interfaces (RS-232, HP-IL, HP-IB). The first Soviet programmable desktop calculator ISKRA 123, powered by the power grid,