DEC's PDP range of computers were small 16 bit machines that had become the mainstay of the small laboratory, especially in universities. The VAX was developed as a 32 bit machine with virtual addressing. It was regarded as a supermini computer having a lot more power than the PDP 11s but not being as expensive as a mainframe computer. The 11/780s, incorporating a networking system called DECNET, were often connected in one of the earliest forms of distributed networks.

The VAX was bought by the Department of Defence in 1984 to replace a PDP 11/40. The PDP 11 was not capable of handling the amount of data that was being collected, or producing the type of graphical result they required. The VAX was purchased after careful comparison with other systems and was eventually chosen over other systems because as well as fulfilling all the requirements it had become an industry standard. It was delivered to the Department of Defence at Wharf 17 in Pyrmont but not installed for 9 months while the air conditioning problems were sorted out. It has been used continuously for data processing on a number of projects. By the 1990s many of the tasks previously done on the VAX could be done much faster on SUN work stations. This has coincided with a general push toward personal computing within the organisation. Despite this movement the VAX 11/780 is to be replaced with a VAX 3100.

This machine also incorporates an array processor. Vector array processors allow for very fast processing of complicated mathematical expressions and can greatly speed the analysis of the huge amounts of data involved in signal processing. The system also incorporates a tektronics high resolution graphics terminal which was able to produce high resolution 3D modelling of processed data. Much of this type of data went to the Navy but some of the work that has been done will be used by commercial enterprises.

Central processing unit, VAX 11/785 computer, metal / plastic electronic components, Digital Equipment Corporation, USA, 1984.

Large beige metal cabinet with a blue top. Two doors give access to the front of the cabinet, two doors at rear. Each door has two stainless steel fasteners. On a grey strip above the doors at the front is the following text - 'Digital VAX11/785', there are then two switches marked 'auto-reset' and 'boot'. To the right of the switches is a row of LEDs marked 'Attn', 'RUN', 'POWER', and 'REMOTE'. After the LEDs is a keyswitch.

Designed: Digital Equipment Corporation; United States of America

Made: Digital Equipment Corporation; United States of America; 1984

Used: Department of Defence; Sydney

95/105/1-2

1550 mm

1060 mm

770 mm