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instructions:bct_pre_omega [2018/03/10 16:34] (current)
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 +===== Branch Communicate (BCT)/OP=30 =====
 +
 +==== Format ====
 +
 +^  OP  ^  AFBF  ^
 +
 +''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 +^ Note | This instruction is obsolete.  |
 +
 +==== Function ====
 +
 +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  ^  :::  ^
 +
 +Toggles:
 +
 +  * 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 ยท Last modified: 2018/03/10 16:34 (external edit)
 
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