Ohio Scientific Instruments

Began operations in Hiram, Ohio around 1975. In Byte #6 there was an advertisement for a 6502 based computer trainer for US$99. This could be traded in on an OSI Superboard kit, or for US$10, for a blank circuit board and a set of instructions for these computers designed by Mike and Charity Cheiky, founders and owners of OSI.

Mike and Charity demonstrated their 400 board at the Trenton NJ Computer Show of 1976, showing how it could be built with either a 6502 or a 6800 processor. This board had space for 8 memory chips, 2102, to provide 1024 bytes. OSI also had video boards and memory boards, and you could buy the bare boards for US$29. The 400 series boards were designed on the basis that
cheap is better, and the 420 memory board took that to the nth degree. No sockets for the memory chips. The board was single sided. The bus was done with Molex pins.

One really nice feature of the OSI boards was they were large and uncluttered, easy to build, and didn't produce as much interference as the more compact designs others used. The top of the line model at this point cost US$675. What is more, you could buy 16K memory boards, an unheard of amount of memory in those days.

The OSI Challenger computer was one of the first personal computers to be supplied with a floppy disk drive, one of the first that could handle multiple users, and the very first to use a Winchester hard drive. This was at a time when computers like the Apple II and TRS-80 were still using cassette tapes.

They had a wide range of 6502 based computers by 1977, ranging from the bare 500 board with 8K BASIC and 4k RAM at US$298, through the CII with a case for US$598, an 8 inch floppy model with 16k of RAM for around US$2000, the CIII with 32k of RAM, two 8 inch floppy drives and serial I/O for US$3481, to a US$6000 addition with a 74 MB hard drive.

OSI provided serial terminal systems, 24x24 character displays, up to 64x32 character displays, sound output as standard. They had voice input boards with a Votrax module, X10 AC control interface boards, joystick boards, ADC and DAC boards, prototyping cards, home security interfaces, a telephone interface, and an eprom burner. Probably the larest range of boards ever to come from one small manufacturer

Unfortunately, the OSI software support was pathetic. Their attitude seemed to be that they produced computers, not manuals. Towards the end they did have three excellent hardware manuals, produced by SAMS as part of their "Photofacts" series. OSI were bought out by MA-COM, who got rid of Mike Chieky, dropped the hobby systems, and eventually went bankrupt.