IBM 727, Руководство по инструкции

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NOTICE
THE text and illustrations in this manual have been prepared
for teaching purposes and as an aid for learning the 727 Tape
Drive and the Tape Drive Tester. All material was prepared
from information relative to production at a given level. En­
gineering changes may alter logic and machine functions. Of
course, these engineering changes could cause the machine’ s
production to be at a different level from that described by this
manual. Therefore, the use of this manual as a reference is
subject to changes in the machine.
One change should be made in the Type 727 Magnetic Tape
Unit Systems book accompanying this write-up for the systems
and write-up to be at the same level, logically. This change
should be made on systems page 75.10. 01 as follows:
1. Remove 12 AU and the lk-ohm potentiometer and 500-
ohm resistor tied to the 12 AUn/o point.
2. Add a jumper from 12 AUn/c to terminal 3.
Doing this rem oves 12 AUn/o and shortens 12 AU n/c. Ma­
chines in the field should already have been changed.
ABBREVIATIONS
The following abbreviations are used throughout this manual.
caps.
capstans
EOT end of tape
EMF
electro motive force
go-fb
go/forward-backward
LP
latch pick
L .P .
load point
LT
latch trip
LRCC
longitudinal redundancy check character
usee
m icrosecond
ms
m illisecond
mtr.
motor
mv
millivolt
MV
multivibrator
NRZI non return to zero
pt. point
PU
pick up
R /W
read-write
sel
select
SS
single shot
TDT
tape drive tester
TI
tape indicator
TU tape unit
tgr.
trigger