RCA 301, Programmer'S Reference Manual

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K Locate Symbol Left (LSL)
General Description
This instruction searches through the contents of successive HSM locations between and including, two specified
addresses. The operation ceases when the rightmost location is reached or upon detecting a non-selected symbol.
Format
Operation — K.
N — Selected symbol.
A Address — Leftmost HSM location to be searched.
B Address — Rightmost HSM location to be searched.
Direction of Operation
Left to right.
Outline of Operation
. , This instruction initially sets PRZ, and operates in the following cycle:
The contents of the A Register are placed in the Memory Address Register. The contents of the A Register are
compared with the contents of the B Register and if this comparison proves equal ABE (A-B Equality) is set; if the
comparison proves unequal ABE is not set. The contents of the A Register are incremented by one.
The contents of the HSM location specified by the Memory Address Register are compared with the contents of
the N Register.
(1) If this comparison proves unequal, and the contents of the Memory Address Register are equal to A
i(
PRN is
set, the contents of the A Register are decremented by two, and the instruction terminates.
(2) If this comparison proves unequal, and the contents of the Memory Address Register are not equal to A
i;
PRP is set, the contents of the A Register are decremented by two, and the instruction terminates.
(3) If this comparison proves equal and ABE is set, the contents of the A Register are decremented by one, and
the instruction terminates.
(4) If this comparison proves equal and ABE is not set, the cycle is repeated.
Standard Location
STA (0212-0215)
Final Register Contents
If a character is found not equal to N
(A)
t
= One HSM address to the left of that character.
(B)
f
= (B),
If all characters searched are equal to the contents of N
(A)
f
= (B)
i
(B), = (B) j
PRN is set when the first character searched is not equal to the contents of N.
PRZ is set when all characters searched are equal to the contents of N.
PRP is set if a non-selected symbol is found in the specified HSM area after a character equal to the contents of
N has been found.
Timing
Total time in microseconds
— I 4n + 56.
n = number of characters searched.
V-5