The number in octal digits 7 through 11 of the instruction word is added to the C(x). This addition is done in the 15 bit Index Adder using 1's complement arithmetic. If, after the addition, the sum is negative, the Program Counter is advanced one extra position and the next instruction in the sequence is skipped. The contents of octal digits 0-5 of the index register location are unaffected by this instruction.
Skip on Positive index(10 usec.)
spx x Y Operation Code 44
The number in octal digits 7 through 11 of the instruction word is added to the C(x). This addition is done in the 15 bit Index Adder using 1's complement arithmetic.
If, after the addition, the sum is positive, the Program Counter is advanced one extra position and the next instruction in the sequence is skipped. The contents of octal digits 0-5 of the index register location are unaffected by this instruction.
Load Index Register(10 usec.)
lir x Y Operation Code 14
The octal digits 7 through 11 (Y) of the instruction will replace the corresponding digits of the memory register specified by x. Octal digit 6 of the memory register will be left clear. Digits 0-5 of the memory register are unchanged.
Deposit Index Adder(10 usec.)
dia x Y Operation Code 16
The C(IA) replace the octal digits 7 through 11 of memory location Y. Octal digit 6 of Y is cleared. Digits 0 through 5 of Y are left unchanged. The x portion of the instruction is ignored.