From Computer History Wiki
Revision as of 15:35, 23 February 2012 by Tor (talk | contribs) (Plural of VAX is traditionally 'VAXen'. Also fixed some very minor issues (it's->its, Mb->MB))
Jump to: navigation, search

The first VAX Introduced in 1977.

Codename: Star
Year Introduced: October 1977
CPU: KA780
Clock Speed: 200 ns
VUPS: 1.0
A 'typical' Vax-11/780 setup.
A real VAX-11/780 install

This was the first VAX from Digital Equipment Corporation. The VAX was the sucessor to the PDP-11, and in order to make the VAX seem more PDP-11 friendly, they retained the -11 monkier for the first VAXen, hence the 11/780 designation. The 11/780 didn't have normal firmware, instead it loaded its microcode from floppy.


SIMH is the only known emulator for the 11/780. Simh can address up to 128MB of RAM emulating an 11/780. Also the following periphals are emulated:

  • CPU VAX-11/780 CPU
  • TLB translation buffer
  • SBI system bus controller
  • MCTL0,MTCL1 memory controllers, MS780C with 4MB memory each, or MS780E with 8MB-64MB each
  • UBA DW780 Unibus adapter
  • MBA0,MBA1 RH780 Massbus adapters
  • TODR time-of-day clock
  • TMR interval timer
  • TTI,TTO console terminal
  • RX console RX01 floppy disk
  • DZ DZ11 8-line terminal multiplexer (up to 4)
  • CR CR11 card reader
  • LPT LP11 line printer
  • RP RP04/05/06/07, RM02/03/05/80 Massbus disks, up to eight drives
  • HK RK611/RK06(7) cartridge disk controller with eight drives
  • RL RL11/RL01(2) cartridge disk controller with four drives
  • RQ UDA50 MSCP controller with four drives
  • RQB second UDA50 MSCP controller with four drives
  • RQC third UDA50 MSCP controller with four drives
  • RQD fourth UDA50 MSCP controller with four drives
  • RY RX211 floppy disk controller with two drives
  • TS TS11 magnetic tape controller with one drive
  • TQ TUK50 TMSCP magnetic tape controller with four drives
  • TU TM03 tape formatter with eight TE16/TU45/TU77 drives
  • XU DEUNA/DELUA Ethernet controller
  • XUB second DEUNA/DELUA Ethernet controller

More information about SIMH's VAX 11/780 emulation can be found here.

Operating Systems

The 11/780 was to ship with VMS 1.0.

There was also the VAX-11/785, which was an upgraded version.