IBM 727, Manual Of Instruction

Page: 34 / 163

Systems Sequence of
Operation
Conditions
Remarks
04D Pick R4, clutch.
R7AL, R2 hold circuit 1/2 power to stop clutches
05E Pick HD6, take-
up motor sta rt. R5AU, R6BL, R7AUn/o Start the take-up m otor.
Start raising the head
cover, and turning the
reels to pull tape from
the columns.
06G
Drop HD8. R7AUn/c The capstans remain r e ­
tracted because of the
mechanical latch.
05F
Pick R8, head
cover not down. Head cover down m icro­
switch. Head cover has just
started up.
06H Drop DP2, cap­
stan mtr.
R8AUn/c
Stop the capstan motor.
02E
Manual start
line up.
R8BL
The unit is now in a fo r ­
ward-start status, placing
the moving pulleys away
from the stop capstans.
05G
Pick R9, RIO,
tape out of
columns. Flapper valve m icro­
switches. Tape out of both columns.
04A
Hold R l, R18,
run. R3AL
05F
Pick R12, high
speed DP3, re ­
wind mtr.
R llA U n /c, head cover
up microswitch, R10AU,
R9AU, R5BL, R6BLn/c,
R7AUn/o.
Indicates tape out of both
columns and head cover
all the way up.
05E
Stop take-up mtr. R12BU
10.01 Remove power from
both stop clutches.
R12AL, BL
No power on any of the
six clutches.
10.02
Start the rewind
mtr. DP3 A, B
Rewind tape at high speed
until 1/2 inch is left on
machine reel.
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