VAX 11/730, VAX 11/725

Introduction
The VAX-11/730, codenamed Nebula, was introduced in April 1982. It was the third VAX introduced, and the slowest implementation of the VAX architecture at 0.3 VUPs. By way of extensive microcoding of the large architecture, the CPU was shrunk to three hex boards. The machine was the first VAX processor to fit on three hex boards and the first VAX to fit in a 10.5" high, rack mountable box. The machine seems to have been most popular for application development projects for the VAX - where the architecture was needed, but not necessarily performance.

SPECIFICATIONS

CPU CPU Module: KA730 Number of Processors: 1 CPU Technology: AMD AM2901 bit slice units CPU Cycle Time: 270ns (3.70MHz) Writable Control Store: 16K X 24-bit words PDP-11 Compatibility Mode: YES Console Boot Processor: Intel 8085 microprocessor, booting from TU58 tape. MEMORY Maximum Memory: 5MBytes Address Lines: 24 Memory Checking: 7-bit ECC Memory cycle: 810ns I/O INTERFACES UNIBUS: 1 at 1.5MB/s LAN Support: optional PERFORMANCE VUPS: 0.3

Source: Text adapted from gunkies.org.

VAX 11/725

Introduced in October 1983, the VAX 11/725 was a lower cost version of the 11/730. It used the same KA730 CPU but was packaged in a smaller enclosure. Its maximum memory capacity was 3 MBytes, but was sold with as little as 1 MByte of memory. The UNIBUS was used for I/O and LAN support was optional. As with the 11/730 it was primarily used as a low cost VMS development system. It could support VMS 3.5 through VMS 5.1.

Sources:

• gunkies.org
• wikipedia.org