Specifications
In
most cases, the word given may be obtained
by
a
status
request
(WES
code)
to
the device.
In
this case, the
status
word is returned
in
the A register. However, when the
device has multiple
status
words (see the device hardware
maintenance
manua!), the
status
word shown here is the
status
word with the appropriate director code.
If
the driver
generates
a composite
status
word for
ESTAT2,
no
status
request loads the word given here into the A register.
I
Conlole
Driver
(752
Terminal)
Status bits for the
752
terminal
are
the same as those for
the
1843-2 Communications Line Adapter described
later
in
this section.
1711/1713
Teletypewriter
Status
Bits
Status
0=1
Ready
1=1
Busy
2=1
Interrupt
3=1
Data
6-8
Description
The teletypewriter power switch
is
in
the on-line position; power
is applied to the teletypewriter.
If
the controller is in read mode,
it
is in the process of receiving a
character
from
the
teletype-
writer, or the holding register
contains data for
transfer
to
the
computer. The busy
status
drops
when the
data
transfer
to the
computer
is
completed, if
data
has not been lost
in
the
mean-
time.
If
the
controller is in write
mode, the
data
register contains
data
and is
in
the process of
transferring
it
to
the
teletype-
writer.
Busy
drops when the
transfer
is complete.
In
either
mode,
the
teletype-
writer mode control relays
are
in
the
process of switching from
one mode
to
another.
An
interrupt condition exists in
the
controller.
If
the controller is in read mode,
the holding register contains
data
for transfer to
the
com-
puter. The
data
status
drops
when the read is completed. One
character
(located in the lower
seven bits of the A register) is
transmitted
at
a time.
If
the
controller is
in
write
mode,
it
is ready
to
accept
another write from the com-
puter. The
data
status
drops
when
the
write is completed.
Status
Bits
Status
4=1
End-of-
operation
5=1
Alarm
6=1
7
8
9=1
10=1
11=1
Lost
data
Not used
Not used
Read mode
Motor
on
(ready)
Manual
interrupt
De8cription
The clutch
in
the teletypewriter
is disengaged. A change of
controller mode may be accom-
plished
at
this time. This
status
is equivalent to a not busy
status.
The ready
status
is a
0,
or
the
lost data
status
is a 1. The
alarm
status
drops when the con-
dition it caused
is
corrected or
when the interrupt request
is
Cleared.
The holding register contained
data
for
transfer
to the com-
puter, and the teletypewri
ter
began to send a new
character
sequence. Lost data
status
may
be cleared
by
a clear controller
function or a
select
write mode
function
after
the
teletypewriter
is stopped and the
character
in
the holding register is read or
when the interrupt request is
cleared.
The controller is conditioned for
input operations.
Identical
to
a ready status;
the
teletypewriter is turned on.
1721/1722/1777
Paper
Tape
Station
Reader
Status
Bits
Status
0=1
Ready
1=1
Busy
2=1
Interrupt
3=1
Data
Description
The paper
tape
reader is opera-
tional.
The paper
tape
reader is busy.
Indicates an interrupt has occur-
red
Indicates the
data
hold register
contains a frame of
data
ready
for
transfer
to the computer.
96769450 B