U UNIVAC 1218 - Bitsavers

7. PARITY SKIP INSTRUCTIONS
The following two instructions permit programmed conditional skips based on
the parity of the bit-by-bit product of the contents of AL and AU. Parity is
odd if the number of ones in the resulting product is odd; parity is even if the
number of ones in the resulting product is even.
50 54
50 55
SKIP ON ODD PARITY (SKPODD)
Execution time: 6 microseconds skip; 4.67 no skip
If the sum of the bits resulting from the bit-by-bit
product of (AL) and (AU) is odd. skip the next instruction;
otherwise, take the next instruction. Ignore k.
(AU)f = (AU)i; (AL)f = (AL)i
Example of skip on odd parity:
.(AU) 000077 mask
(AL) 127723
bit-by-bit product = 000023
bit sum = 3
Since the bit sum is odd. the next instruction is skipped.
SKIP ON EVEN PARITY (SKPEVN)
Execution time: 6microseconds skip; 4.67 no skip
If the sum of the bits resulting from the bit-by-bit
product of (AL) and (AU) is even, skip the next
instruction; otherwise, take the next instruction.
Ignore k.
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