RCA 301, Programmer'S Reference Manual

Page: 124 / 235

S Automatic Rollback Control (IOS)
General Description
This instruction will allow the computer program to override the hardware rollback capabilities of the Model
382 and Model 582 Tape Stations. Immediate stopping will occur on all read and/or read after write errors.
34
Format
©4
G t ^ Use trs
Operation — S
N
Device
N
Device
Unit #1
Unit #2
Hi-Data Tape Group, 30 KC
66 KC Adapter
123456
L
ABCDEF
P
A Address — A
0
— Must be zero (0).
Ai — 4 Allow hardware rollback.
8 Don't allow hardware rollback.
A
2
, A
3
— Must be zeros (00).
B Address — Must be zeros (0000).
Outline of Operation
The command called for by the one bits in Aj.are sent to the control module selected by N. If the "don't allow
hardware rollback" option is selected, the computer will halt on all read and/or read after write errors. If the
"allow hardware rollback" option is selected, automatic hardware rollback will be initiated on all read and read
after write errors.
Final Register Contents
(A)
f
= (A)
(
(B)
f
= (B)i
Timing
42 ju.s.
IX-16