Modem Mode 2·12 - IBM 5100 Maintenance Information Manual

When operating the serial I/O feature, the user can select
one of four modes (modem, ignore, terminal, or set). In
modem or ignore mode, the 5100 functions like a modem
(data set). In terminal mode, the 5100 functions like a
terminal and in set mode, the 5100 can function as either
a terminal or a modem (either the modem cable or the
terminal cable can be used to attach the I/O device).
Modem Mode
Because the 5100 operates like a modem (data set) in
modem mode and the expansion feature card is designed for
communications terminal operations, the line names are
interchanged at the seriai i/O connector as foiiows:
Data terminal ready with data set ready
Request to send with clear to send
And transmitted data with received data
The following diagram shows the EIA standard interface
lines that are used during serial I/O operations and the way
they are connected to the 5100 in modem mode. Refer to
the IBM 5100 Maintenance Information Manual for the
serial I/O connector and Z1 cable socket pin numbers.
Base I/O
Card (F2)
2-12
Bus Out
--.
....
Bus In
~
Device Adr Bus ..
. .
Control
+ext horiz dr
Expansion
Feature Card (B2)
'+510 data term rdy'
'+510 data set rdy'
'+510 request to send'
'+510 clear to send'
'+SIO xmit data'
'+510 rcvd data'
'+510 rcvd line sig def
Signal ground
Protective ground
Z1 Cable
Socket
\
Serial I/O
Connector
Serial I/O Device
I
r------,
J><[
1><1
J><[
L _____
.J
I
Internal
Cable
0:------,
_.
Data Terminal Ready
Data Set Ready
I
Request To 5end
Clear To Send
Transmitted Data
Received Data
Received Line
Signal Detector
Signal Ground
Protective Ground
L _____
,
Serial I/O
Modem Cable