Ohio Scientific Inc.

Ohio Scientific Inc.
Founding Date Jan 1975 (46 years ago)
Number of Employees 1000

Ohio Scientific Inc. (also known as Ohio Scientific Instruments) was a United States computer company that built and marketed microcomputers from 1975 to 1981. Their best known products were the Challenger series of microcomputers, but they also sold a variety of computer kits, single-board computers and various peripherals.

The company was founded by Mike and Charity Cheiky in 1975 in Hiram, Ohio. Their earliest products were MOS 6502-based systems, the same processor used in the Apple II and many other early micros. The company initially sold a computer trainer, which consisted of the 6502 and enough circuitry to communicate with the processor using switches. This was first advertised for $99 in the February 1976 edition of Byte Magazine.Stan Veit, "The Ohio Scientific", PC-History, Stan Veit's History of the Personal Computer, WorldComm, 1993

If the trainer was successfully assembled, the owner could trade it, along with another $10, for the company's "OSI 400 Superboard System", a fully developed single-board microcomputer that could run with either the 6502 or the Motorola 6800. The bare boards were available for as little as $29, or in a variety of kit versions with more or less of the parts needed to build it out. It could support up to eight National Semiconductor 2102 SRAM memory chips for 1024 bytes (1 KB) of RAM, 512 bytes of ROM, an ACIA serial interface chip for RS-232C or a 20 mA current loop interface for a teletype, a PIA for 16-parallel I/O lines, and a power supply. Adding a terminal or teletype completed the system. The company also sold one of the earliest floppy disk interfaces and a video card for use with a composite monitor.