VAXstation 100

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Graphic displayed when the VAXstation 100 has powered up and finished self testing. Push any mouse button to log in to the host.

The VAXstation 100 was a programmable graphics terminal manufactured by DEC. It had a bit-mapped display, and could accept, for presentation to the user, text, diagrams or images (when running its usual on-board program, in its microprocessor).

It consists of a separate chassis containing a 'display processor module', which is attached remotely to a 'bus window module' in the host computer, which is connected to the other module via fiber optic cables. The VR100 display (a CRT capable of 1,088x864 pixels resolution) was attached to the display processor module, along with a keyboard and mouse. (The chassis contained a separate power supply.)

The display processor module used a Motorola MC68000; it had 128K bytes of main memory, in addition to the 512K bytes of memory for the bit-mapped display (only 1/4 of that actually drove the display; the rest could be used to hold data such as fonts). Bootstrap and diagnostic code was contained in PROMs; operating object code was downloaded over the fiber link once the VAXstation 100 had powered on. A 'Bit Blit Accelerator module' was attached to the display processor module; it used a separate bus to get to the screen memory. The BBA off-loaded some laborious low-level tasks (such a copying an area of the display to somewhere else, e.g. in moving a window) from the microprocessor, and performed them as quickly as possible.

The only bus window module available, the UNIBUS Window Module, was a hex card, the M7452, which plugged into a standard MUD slot. Although in theory a VAXstation 100 could be attached to any host with a UNIBUS, DEC only supported them on VAXen running VMS. Software in the VAXstation 100 and VMS represented the VAXstation 100 as a series of terminals (one for each open window) to VMS.

The VAXstation 100 is of some historical note due to its role in the development of the X Window System. Babara Liskov's CLU group had acquired a number of VAXstation 100 terminals and needed a windowing system running on Berkeley Unix. Initially the W window system was used, but Bob Scheifler largely re-wrote it to become X.

Software support

  • 4.3 BSD comes with a driver for the VAXstation 100 called vs.c.
  • VMS has a layered product called VAXstation Software; see below.
  • The X Window System supports the VAXstation 100 from the initial version, to X10R4.
  • MIT Project Athena had a terminal emulator that handled multiple VAXstation 100's. It was maybe called vsterm, and was possibly written in CLU.

See also

External links