IBM Series 1 User Manual page 242

TNL: GN34-0368 to GA34-0033-0 (February 4, 1977)
TELETYPEWRITER ADAPTER DESIGN CONSIDERATIONS
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The teletypewriter should be configured for full duplex
operation and
a
20
rnA
current loop prior
to
installation.
Teletype* Models ASH 33, ASR 35,
or KSH 33 are normally
shipped from
the
factory wired for
half
duplex,
60 rnA, and
even parity.
The isolated contact
sense
input, with input
selection
code equal to all zeros, must be used tor connection of the
ASH 33/35.
Either the current driver, current=mark output or the
solid state switch, closed=data mark output must be used for
the ASH 33 and 35.
If
the system is
powered down, the
output
driver
goes
to a data. space condition causing the device to "chatter" if
it is in
uline
mode". Consequently
the ASH 33/35
should
be
turned off or put in local mode it
the
system is powered
down. However, no damage
to the device results if
it is
left in line
mode, just unnecessary wear.
Also
if
the
cable is
disconnected while
the
ASH 33/35
is in line mode, the devica Cdn chatter.
During an IPL operation, the ASH 33/35 should be placed
in line mode prior to pressing the Load key on the processor
console.
The tables in the following subsections indicate how pins of
the top-card connector should be connected to pins on the
attached device.
B1A. The communications power supply feature furnishes
i12
volts. This feature is a prerequisite for any card file
{except the 4953-A
Processor}
in which the
teletypewriter
(TTY) adapter is installed if the adapter sends EIA output
levels to the device. However, the 12 volt supply is not
required to only receive EIA levels. The connections for EIA
are as follows:
Series/lTTY card connector
A4 EIA received data in
A6 Data terminal ready
B5 Signal ground
B6 EIA transmitted data
Device connector
EIA transmitted data
Received line signal detector
Signal ground
EIA received data
Connect "request to send"
to "clear to send"
Connect "data terminal ready"
to "data set ready"
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*Registered trademark of Teletype Corporation
Teletypewriter Adapter 4-2Y