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UNIVAC 1100/2200 series

The UNIVAC 1100/2200 series is a series of compatable 36 bit computer systems initially made by Sperry Rand. The series continues to be supported today by Unisys Corporation.

Table of contents
1 Architecture

    Architecture 

Instruction format

Instructions are 36 bits long with the following fields:

f ( 6 bits) - function designator (opcode),
j ( 4 bits) - partial word designator, J-register designator, or minor function designator,
a ( 4 bits) - register (A, X, or R) designator or I/O designator,
x ( 4 bits) - index register designator,
h ( 1 bit ) - index register increment designator,
i ( 1 bit ) - indirect address designator,
u (16 bits) - address or operand designator.

Address Register Contents
000 Unused Unused
001 X1 Increment Modifier
... ... Increment Modifier
013 X11 Increment Modifier
014 X12/A0 Overlap (X or A)
... ... Overlap (X or A)
017 X15/A3 Overlap (X or A)
020 A4 Accumulator
... ... Accumulator
033 A15 Accumulator
034 A15+1 Unassigned (A)
... ... Unassigned (A)
037 A15+4 Unassigned (A)
... Executive Protected Executive
101 R1 Special (R)
... ... Special (R)
117 R15 Special (R)
... Executive Protected Executive
177 Executive Protected Executive

Registers

The 128 registers of the high speed "general register stack", map to the current data space in main storage starting at memory address zero. These registers include both user and executive copys of the A, X, R, and J registers and many special function executive registers.

The table on the right shows the addresses (in octal) of the user registers.

There are 15 index registers (X1 ... X15), 16 accumulators (A0 ... A15), and 15 special function user registers (R1 .. R15). The 4 J registers and 3 "staging registers" are uses of some of the special function R registers.

One interesting feature is that the last 4 index registers (X12 ... X15) and the first 4 accumulators (A0 ... A3) overlap, allowing data to be interpreted either way in these registers. This also results in 4 unassigned accumulators (A15+1 ... A15+4) that can only be accessed by their memory address (double word instructions on A15 do operate on A15+1).

    UNIVAC 1100 series 

  1. UNIVAC 1107 introduced in 1962
  2. UNIVAC 1108 introduced in 1964
  3. UNIVAC 1106 introduced in 1969
  4. UNIVAC 1110 introduced in 1972
  5. UNIVAC 1100/10[?] introduced in 1975
  6. UNIVAC 1100/12[?] introduced in 1975
  7. UNIVAC 1100/20 redesignation of UNIVAC 1106 in 1975
  8. UNIVAC 1100/40 redesignation of UNIVAC 1110 in 1975
  9. UNIVAC 1100/181[?] introduced in 1975
  10. UNIVAC 1100/80[?] introduced in 1978
  11. UNIVAC 1100/60[?] introduced in 1979
  12. UNIVAC 1100/61[?] introduced in 1979
  13. UNIVAC 1100/62[?] introduced in 1981
  14. UNIVAC 1100/63[?] introduced in 1981
  15. UNIVAC 1100/64[?] introduced in 1981
  16. UNIVAC 1100/70[?] introduced in 1981
  17. UNIVAC 1100/90[?] introduced in 1982
  18. UNIVAC 1100/91[?] introduced in 1982
  19. UNIVAC 1100/92[?] introduced in 1982
  20. UNIVAC 1100/93[?] introduced in 1982
  21. UNIVAC 1100/94[?] introduced in 1982

    SPERRY 2200 series 

In 1983 Sperry Corporation discontinued usage of the name UNIVAC for their products.

  1. SPERRY 2200/100[?] introduced in 1985

    UNISYS 2200 series 

In 1986 Sperry Corporation merges with Burroughs Corporation to become Unisys Corporation.

  1. UNISYS 2200/200[?] introduced in 1986
  2. UNISYS 1100/94[?] introduced in 1987
  3. UNISYS 2200/400[?] introduced in 1988
  4. UNISYS 1100/91[?] introduced in 1988
  5. UNISYS 1100/92[?] introduced in 1988
  6. UNISYS 2200/600[?] introduced in 1989
  7. UNISYS 2200/100[?] introduced in 1990
  8. UNISYS 2200/500[?] introduced in 1993
  9. UNISYS 2200/900[?] introduced in 1993
  10. UNISYS 2200/3800[?] introduced in 1997

    External link