Heathkit H11

The Heathkit H11 Computer is an early kit-format personal computer introduced in 1978. It is essentially a Digital Equipment PDP-11 in a small-form-factor case, designed by Heathkit. The H11 is one of the first 16-bit personal computers, at a list price of US$1,295, but it also requires at least a computer terminal and some form of storage to make it useful. It was too expensive for most Heathkit customers, and was discontinued in 1982.

Specifications
The H11 featured:
 * Processor — LSI-11 (KD11-HA half-size or "double-height" card)
 * Speed     — 2.5 MHz
 * ROM       — 8 kWords (16 KB) (max)
 * RAM       — 32 kWords (64 KB) (max)
 * Slots     — 7 Q-bus slots
 * Storage   — H27 8-inch floppy drive (2 256 KB 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
 * Languages — BASIC, Focal and others

Initial memory limitations restrict the selection of system software, but the system RAM can be expanded to 32 kWords * 16 bit. Many PDP-11 operating systems and programs run without trouble. The system will also work with most DEC PDP-11 equipment, including many Q-bus compatible peripherals.