(10) EOT STAT (End of Tape Status). A low
deck assembly. RDY STAT, REWIND STAT, BOT
level indicates that the photosense assembly has
STAT, and EOT STAT are generated by status
sensed the end-of-tape marker. The signal will
gating logic U 17 and routed to the interface. Input
remain low as long as the EOT marker is past the
signals asociated with the tape motion command
photosense assembly. The signal is reset when the
logic are described below.
EOT marker passes the photosense assembly in
(1) HIGH/LOW (Fast/Slow Speed Select). A
reverse direction. Data can be transferred past the
logic low specifies low tape speed. A logic high
EOT marker until an EOT hole is sensed. When an
specifies fast tape speed.
(2) FWD/REV (Forward/Reverse). Upon receipt
EOT hole is sensed an automatic rewind to the BOT
of a RUN CMD, the tape will be driven forward for a
marker occurs. The low EOT STAT signal is
logic low signal and driven in reverse for a logic high
produced by the EOT FF input going high.
The tape motion output signals FAST FWD and
REVERSE are decoded from the HIGH/LOW,
(3) RUN/STOP. The tape will move in the
FWD/REV, and RUN/STOP control signals from
direction specified by the FWD/REV command
the interface. FAST RVS can be initiated by the
when the signal is at a logic low. The tape movement
above control signals or by REWIND, by the tape
will stop when the signal is a logic high.
status signal END HOLE, and by depressing the
(4) END HOLE. The signal is at logic high
front panel RWND switch (RWND SW signal).
when a hole at the end of the tape is sensed.
REWIND, END HOLE and RWND SW set the
(5) BEG HOLE. The signal is at logic high
rewind flip-flop U11 which outputs RWND FF to
when a hole at the beginning of tape is sensed.
the tape motion control rewind logic. The FWD
(6) BOT (Beginning of Tape). The signal is at
output is either decoded directly from the interface
logic high when the reflective strip at the beginning
control signals or is intiated by BEG HOLE which
of tape is sensed.
sets the beginning of tape flip-flop U7, U8. The tape
(7) EOT FF (End of Tape Flip Flop). The signal
motion output signals are high when active, and are
goes to logic high when the reflective strip at the
routed to the servo control circuit card (A5, fig. 1-2).
end of tape is sensed. The signal remains high until
RESET is also supplied to the servo control circuit
the strip is again sensed after the tape motion is
card. A low level on RESETS the end of tape
flip-flop. A high level on RESET enables the flip-
(8) REWIND STAT (Rewind Status). A logic
low indicates that the recorder is rewinding. The
signal remains low until tape motion has stopped
2-9. Servo Control Circuit Description
and the BOT marker is sensed. Rewind is initiated
by either an external command (REWIND) or by
a. General. The servo control circuit card (A5, fig.
the RWND switch on the front panel. Either signal
is a part
of the capstan motor velocity servo
sets flip-flop" (U11-A, B). The flip-flop is reset when
loop. This card generates a dc servo error signal
the BOT signal becomes low.
which controls the speed and direction of the cap
(9) BOT STAT (Beginning of Tape Status). A
low level signal indicates that the photosense
mounted on the capstan motor shaft nulls the error
assembly is sensing the BOT marker. During rewind
signal when the motor reaches the correct rotational
the BOT marker may be passed in reverse. After the
velocity. Use the Servo Control Circuit Card
tape has stopped, forward motion commences and
stops when the leading edge of the marker is sensed.
BOT STAT remains low only as long as the BOT
marker is being sensed.