Processor Technology was launched in 1975 by Bob Marsh as a manufacturer of 4K memory boards for the MITS Altair. Lee Felsenstein, who would later design the Osborne 1, created the Sol-20 the following year for Marsh. It was one of the more attractive computers of the era, with a bright blue metal case and finished wood sides. An estimated 20,000 Sol-20s were made before Processor Technology went out of business in 1980. The optional Helios drives had a reputation as being unreliable, and many Sol-20 owners opted for 5.25-inch drives made by North Star. A Sol-10, which lacked the S-100 bus, was also sold as a terminal.
Processor Technology Sol-20 (1976, early micro)
Original Retail Price: $995 kit, $2,129 assembled
Base Configuration: 8080A CPU, SOLOS, five S-100 slots, 2K RAM (64K max), 1K ROM (2K max), cassette recorder, 12-inch monochrome TV/monitor, integral keyboard, RS-232 and cassette ports
Video: 16-line x 64-column text
Important Options: 8080A or 9080A CPU, external Helios II dual 8-inch floppy disk drives