TM
11-5835-243-34/EE641-AA-MMI-010/E154
MTT/TO
31S3-4-110-1
b. Reverse Tape Motion. In the tape reverse mode
terclockwise (fig. 2-2). Tape tension is developed in
both belt idlers and the floating pressure roller are
a similar manner to that described for forward tape
driven clockwise and the reels are driven coun-
motion.
Section Il. DETAILED FUNCTIONAL DESCRIPTION
2-6. Logic Definitions
c . Output Driver Capabilities.
(1) Standard Voltage Levels:
a. Input/Output (I/O) Logic Level Definition The
LOW level (logic 1): . . . . . . . . . .0.2 to +0.5 volt
following logic definitions are used to describe the
HIGH level (logic 0): . . . . . . . . . +2.5 to +4.5 volts (5.5V max.)
I/O logic requirements:
(2) Standard Current Levels:
(1) LOW. Indicates the relatively low input
Low (logic 1)". . . . . . . . . . . . . . . . 100 mA maximum
level or pulse to the line receiver that controls the
HIGH (logic 0):. . . . . . . . . . . . . . Outputs are open collector
and require an external pull-
active state of that functional (logic '1').
up resistor 220 to 330 ohms
(2) HIGH. The relatively high input level or
nominal.
pulse that indicates logic `0'.
2-7. Digital Read Write Circuit Description
(3) PULSE. A relatively low level which has a
time duration of less than 10 microseconds.
a. General. The tape transport uses three digital
(4) LEVEL. A relatively low level which has a
read/write circuit cards (A1, A2, A3). Each card
time duration of greater than 10 microseconds.
contains three identical digital read/write amplifier
b. Input Requirements. Input requirements for
sections, providing a total of nine read/write data
the tape transport are listed below:
channels. For example, AR1 serves as read amplifier
(1) Standard Voltage Levels:
for channels 3, 6, or 9 depending on card location
LOW level (logic l): . . . . . . . . . .0 to +l.2 volts
(XA1, XA2, or XA3). This paragraph describes just
HIGH level (logic 0): . . . . . . . . . +2.5 to +4.5 volts
one of the read/write amplifier sections on a circuit
( 2 ) Standard Current Levels:
card, but applies equally to all nine. Use the Digital
LOW (logic l): . . . . . . . . . . . . . . . + 0.1 mA maximum (from
Read/Write Circuit Card Functional Block Diagram
receiver)
HIGH (logic 0): . . . . . . . . . . . . . . - 0 . 1 m A m a x i m u m ( f r o m
with the following description.
receiver)
2-5
