transferred, .!lQ record-length interrupt occurs
and the channel can command chain to aWrite to send the "V" answerback to the polled
station. This permits the station to start its
tape reader and continue to send the message.
4. If another reply to the poll is received under
theSearch, the 2703 will scan the data on the
line until it recognizes theEOT sequence
(FIGS-H,LTRS), at which point it transfers
the"H" to the processor and ends the command
withChannel End, Device End, and Unit
Exception status. No transfer of data occurs
during this scan.
5. TheWrite command should then be command
chained to a Read to receive the message.
6. Line timcouts are active during execution of
theSearch command. If the first address on
the tape begins with"A" but is not "AZ", the "A" will be transferred to the processor, but
otherwise the operation is normal; the"H" of the EOT sequence will be placed in the next
position in core storage.
Character-RecognitionSummary The following characters are recognized during
write-type operations:
1. InLTRS mode, any character with the S bit ON causes the line to send the FIGS character
and set the shift bit before it is transmitted.
2. InFIGS mode, any cn'lracter with the S bit OFF causes the line to send the LTRS charac
ter and reset the shift bit before it is trans
mitted.
3. If wired for "unshift on space" operation, the
space character setsLTRS mode. In this
case, theS bit accompanying the space charac
ter is ignored.
The following characters are recognized during
read-type operations:
44
1. A"V" (or "M") received as the first character
w ill set End status.
2.FIGS-H, LTRS received as EOT (end of trans
mission) sets End and Unit Exception status.
3. The two-character processor address"AZ", if received as the first two non-letters
characters of a message under theSearch command, will set End.
4.LTRS (letters shift), which sets downshift (0 in the S bit) if the line was in Ufshift (1 in
theS bit). In any case, this terminal control
inhibits transfer of this character to theI/O channel, removing it from the incoming data
stream.
5.FIGS (figures shift), which sets FIGS mode if
the line was inLTRS mode, and has no effect
if the line was already inFIGS mode. In any
case, this terminal control inhibits transfer of
this character to theI/O channel, removing it
from the incoming data stream.
6. If wired for "unshift on space" operation, the
space character sets downshift(0 in the S bit)
when it is received. The space character is
thcn transferred to theI/O channel with its S bit zero.
Telegraph TerminalControl Type II
This feature provides the controls necessary for the
attachment of Teletype Corporation's Models 33 and
35 Teletypewriter terminals to the2703. Operation
is point-to-point and, generally, on a dial-up basis.
The transmission speed is110 bps, with an eight
bit data code. The code employed is the eight-bit
data-interchange code with the following relationship
to the System/360 interface:
o 234 567System/360 Byte
2345678 35 Teletype CodeOne start bit and two stop bits are transmitted and
received by this terminal control.
Identification answerback from the2703 is handled
by the processor. Output messages may be of any
length or format. Input messages may be of any
length. However, certain format restrictions are
imposed due to the line control adopted by these
terminals.On input, or during read-type operations,
the following characters are recognized by the2703; they cause termination of the I/O operation, with
subsequent interruption of the CommunicationsIOCS: 1. WRU--"Who are you"--which causes End
status in theLCW. 2. XOn--"Transmitter on"--which causes End
status in theLCW. 3. XOff--"Transmitter off"--which causes End
status in theLCW. 4. EOT--"end of transmission"--which causes End
and Unit Exception status in theLCW. 5. The delete character (all Marks) is recognized
by the terminal control. Transfer of deletes
to theI/O channel is inhibited during all read
type operations.
The Break signal may be detected during trans
mission. If the receive-data lead at the data set is
atSpace for two successive transmit-start times,
the write operation is term inated with Channe lEnd,
Device End, and Unit Check status, and Intervention
Required is set in the sense field.
and the channel can command chain to a
station. This permits the station to start its
tape reader and continue to send the message.
4. If another reply to the poll is received under
the
line until it recognizes the
(FIGS-H,
the
with
Exception status. No transfer of data occurs
during this scan.
5. The
chained to a Read to receive the message.
6. Line timcouts are active during execution of
the
the tape begins with
otherwise the operation is normal; the
position in core storage.
Character-Recognition
write-type operations:
1. In
and set the shift bit before it is transmitted.
2. In
ter and reset the shift bit before it is trans
mitted.
3. If wired for "unshift on space" operation, the
space character sets
case, the
ter is ignored.
The following characters are recognized during
read-type operations:
44
1. A
w ill set End status.
2.
mission) sets End and Unit Exception status.
3. The two-character processor address
characters of a message under the
4.
the
inhibits transfer of this character to the
stream.
5.
the line was in
if the line was already in
case, this terminal control inhibits transfer of
this character to the
from the incoming data stream.
6. If wired for "unshift on space" operation, the
space character sets downshift
when it is received. The space character is
thcn transferred to the
Telegraph Terminal
This feature provides the controls necessary for the
attachment of Teletype Corporation's Models 33 and
35 Teletypewriter terminals to the
is point-to-point and, generally, on a dial-up basis.
The transmission speed is
bit data code. The code employed is the eight-bit
data-interchange code with the following relationship
to the System/360 interface:
o 234 567
2345678 35 Teletype Code
received by this terminal control.
Identification answerback from the
by the processor. Output messages may be of any
length or format. Input messages may be of any
length. However, certain format restrictions are
imposed due to the line control adopted by these
terminals.
the following characters are recognized by the
subsequent interruption of the Communications
status in the
status in the
status in the
and Unit Exception status in the
by the terminal control. Transfer of deletes
to the
type operations.
The Break signal may be detected during trans
mission. If the receive-data lead at the data set is
at
the write operation is term inated with Channe lEnd,
Device End, and Unit Check status, and Intervention
Required is set in the sense field.