Heathkit H11

The Heathkit H11 Computer was an early kit-format personal computer introduced in 1978. It was essentially a Digital Equipment PDP-11 in a small-form-factor case, designed by Heathkit. The H11 was one of the first 16-bit personal computers, at a list price of US$1,295,[1] but was too expensive for most Heathkit customers and was discontinued in 1982.[2]

Specifications

The H11 featured:[3]

•     Processor — LSI-11 (KD11-HA half-size or "double-height" card)
•     Speed — 2.5 MHz
•     ROM — 8KB (max)
•     RAM — 32KB (max)
•     Slots — 7 Q-bus slots
•     Storage — H27 8-inch floppy drive (2 256k 8-inch single sided drives) or paper tape
•     I/O — serial (RS-232) or parallel ports
•     Operating system — HT-11 (a simplified version of RT-11)
•     Instruction set — PDP-11/40 instruction set which included over 400 instructions[citation needed]
•     Languages — BASIC, Focal and others

Initial memory limitations restricted the selection of software the system could handle, but the system could be expanded to 32KB of RAM. Many PDP-11 operating systems and programs ran without trouble. The system would also work with most DEC PDP-11 equipment, including many Q-bus compatible peripherals.