2020-9-16

The calculator is generally composed of an operator, a controller, a memory, a keyboard, a display, a power supply, and some optional peripherals and electronic accessories, which are composed of manual or machine equipment. The low-end calculator’s operator and controller are implemented by digital logic circuits for simple serial operations. The random access memory has only one or two units for accumulating storage. The high-end calculator implements various complicated arithmetic programs by a microprocessor and a read-only memory, and has more random storage units for storing input programs and data. The keyboard is the input component of the calculator and is generally contact or sensory. To reduce the size of the calculator, one button often has multiple functions. The display is the output part of the calculator, such as a light-emitting diode display or a liquid crystal display. In addition to displaying calculation results, there are often overflow indications, error indications, and the like. The calculator power supply uses an AC adapter or battery, and the battery can be recharged with an AC adapter or a solar energy converter. In order to save power, the calculators use large-scale integrated circuits (see complementary metal-oxide-semiconductor integrated circuits) fabricated in CMOS technology, and are equipped with timing-non-operating automatic power-off circuits. The peripherals that can be used in the calculator are micro printers, cassette tape recorders, and magnetic card machines.