Harris H series

The Harris H series computers began with the Slash 1, or DC 6024, offered by Datacraft Corporation in 1969. Harris acquired Datacraft in 1974 and kept the Slash name for a while. The first H branded computer, the H-100, was released in 1978. In the early 1980s, the H series extended into the super-mini segment. One of the last models was the H-1600 in 1987.

The integer ALU width was 24 bits; floating-point numbers were 48 bits. The instruction set had support for double-width integers, and a full 48-bit ALU appearing in late hardware iterations. Addressing is by word. Instructions were originally all 24 bits; later architectural updates came with some two-word instructions.

Early operating systems were DOS-II—Disc Operating System, and DMS—Disc Monitor System. The Harris machines ran the virtual memory operating system VULCAN—Virtual Core Management Operating System, later replaced by the newer VOS—Virtual Operating System.

The architecture evolved over the years:

• The compatibility C-mode had a 16-bit address space.
• The address extension X-mode had a 20-bit address space.
• The full address F-mode expanded 48-bit integer capabilities in the instruction set.

In the late 1980s, Harris sunset the H series in favor of a new 32-bit Tahoe based CX series.

External links

• Datacraft documents at Bitsavers
• Harris documents at Bitsavers
  • Evolution of the Harris H-series
  • VULCAN software at Bitsavers