Branch Communicate (BCT)/OP=30



OP = 30

AFBF Is the communicate address which is the low order four digits of an absolute machine address. The high order digits are equal to zero. Indirect field length can be specified.

Note This instruction is obsolete.


Typically the Branch Communicate instruction is used to branch from an object program to a control program pointer located at the Communicate address. The control program pointer must contain a hex F as the most significant digit if the instruction is to be valid. The following processor information is stored in absolute memory locations 61 through 76.

61 62 63 - 69 70 - 72 73 - 75 76
Base Digit Limit Digit Next Program Instruction Address Base Digits Limit Digits Toggles
7 7 6 - 4 6 - 4


  • Bit 8 Unused
  • Bit 4 Overflow
  • Bit 2 Comparison LOW
  • Bit 1 Comparison HIGH

Comparison Flags

The comparison flags are unchanged.

Overflow Flag

The overflow flag is unchanged.

instructions/bct_pre_omega.txt · Last modified: 2018/03/10 16:34 (external edit)
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