Heathkit H8

Summary

Heathkit is known in the USA for electronics kits, from radios to measuring instruments. In July 1977, it announced the H8 kit computer, costing US$379 as a kit or $475 assembled as the WH8. Its processor is an Intel 8080A. Instead of the widespread S-100 bus, Heathkit uses its own ten-slot, 50-pin “Benton Harbor Bus”, named after the company’s home town. A front-panel keypad and seven-segment display provide control through the PAM-8 monitor program in ROM.

For useful work, the computer needs a 4 KB memory card. Programs arrive on paper tape or cassette, and from 1978 also through the H17 disk system. Operating systems include HDOS and CP/M. The H89 followed in 1978 with a Z80 and built-in terminal; Zenith later sold it as the Z89. H8 production ended in 1981 because it did not meet new FCC radio-interference requirements.