RCA 301, Programmer'S Reference Manual, Page: 125 / 235

S Sense Read Error (IOS)
General Description
This instruction is to be used in conjunction with the Read Error Sense Enhancement for Model 381 Tape
Stations. It has two functions as follows:
1. Set the Program Control Switch
Format
Operation —S
N —M
A Address — A
0
, A
u
A
2
— Must be zeros (000).
A
3
— 1 Set Read Error Sense Enhancement OFF.
— 2 Set Read Error Sense Enhancement ON.
B Address — Must be zeros (0000).
2. Sense for Read Parity Error (RE)
Format
Operation — S
N —M — First Control Module 318 (1-6).
& — Second Control Module 319 (A-F).
A Address — A
0
= 4 Sense for Read Parity Error.
A„ A
2
, A
3
— Must be zeros (000).
B Address — HSM location of the next instruction to be executed when the Read Parity Indicator is sensed and
found set.
Standard Location
STP (on transfer only)
Note: The A
0
and A
3
options cannot be used in combination. Therefore, an IOS instruction should be used for
setting the Programmed Control Switch and another IOS instruction should be given for the test function.
Outline of Operation
The Programmed Control Switch is set ON or OFF by the proper bit setting in A
3
. The test called for by the
4 in A
0
is performed on the control module selected by N. If the condition tested (RE) is present, the contents of
the P Register are transferred to STP and the contents of the B Register are then transferred to the P Register.
If no tested condition is present, the next instruction in sequence will be executed.
Final Register Contents
(A), = (A),
(B)
f
= (B),
Timing
Function 1
42 IXS.
Function I
56 /is if a transfer is executed.
42 fis if no transfer takes place.
IX-17