VAX 8000

The VAX 8000 was a family of minicomputers developed and manufactured by Digital Equipment Corporation (DEC) using processors implementing the VAX instruction set architecture (ISA).

VAX 8600

The VAX 8600, code-named "Venus", introduced in October 1984, was the successor of the VAX-11/785. It was originally to be named "VAX-11/790", but was renamed before launch. The VAX 8600 was a successful model and at the time was the best selling high-end VAX. It was succeeded by the VAX 8800 family in 1987.

The VAX 8600 had a CPU with an 80 ns cycle time (12.5 MHz) implemented with emitter coupled logic (ECL) macrocell arrays (MCAs). The CPU consisted of four major logical sections, the E Box, F Box, I Box and M Box. The E Box executed all instructions, including floating-point instructions through microcode. It had an arithmetic logic unit (ALU) and barrel shifter. The F Box, or floating point accelerator (FPA), was an optional feature that accelerated floating-point instructions as well as integer multiplication and division. It was a two-module set consisting of an adder module and multiplier module. The adder module contained 24 macrocell arrays while the multiplier module contained 21. The I Box fetched and decoded instructions. The M Box controlled the memory and I/O, translated virtual addresses to physical addresses and contained a 16 KB data cache.