TINY-2/MICRO-2 Technical Ref., 2. Ed 1989
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Data Carrier Detect (DCD) is an output from the packet controller. DCD reflects the status of
the CON LED: It is high when a packet connection exists and it is low when no connection ex-
ists. This Signal is useful when the packet controller is used with telephone style and BBS soft-
ware, since the connect signal, like a modem carrier on the telephone, indicates the presence
of a user.
Data Terminal Ready (DTR) is an input to the TINY-2/MICRO-2 signaling that the attached
computer terminal device is ready to accept data from the packet controller. Not used on the
TINY-2/MICRO-2.
The table below provides a cross reference to the pinouts of the industry standard 25 pin connec-
tor as used on many computers and terminals. The TNC-2 and PacComm TNC-200, and relates
them to the newer 9 pin connectors used on many modem computers and the TINY-2/MICRO-2.
Note that connecting a DTE device to a DCE device using either 25 pin connectors or 9 pin connec-
tors at both ends of the cable provides a 'straight through' wiring of pin numbers, i.e. connect col-
umn 1 to column 4 OR connect column 2 to column 3. However, when a 25 pin connector and 9
pin connector are used on the same cable, i.e. column 1 to column 3, several pairs of signal lines
must be crossed.
TINY-2/MICROPOWER-2 RS-232 Serial Port Signal Cross Reference
Conventional
RS-232
Conventional
RS-232 DTE DB-25
IBM AT
RS-232 DTE DE-9P
TINY/MICRO
RS-232 DCE DE-9P
TNC-2(00)
RS-232 DC DB-25
Definition
Pin Nr.
Pin Nr.
Pin Nr.
Pin Nr.
FG
TXD
RXD
RTS
CTS
DSR
SG
DCD
Test
Test
DTR
RI
1
2
3
4
5
6
7
8
9
10
20
22
shell
3
2
7
8
6
5
1
V+
V-
4
9
5
3
2
7
8
6
5
1
a
-
-
nc
9
b
1
2
3
nc
5
6
7
8
a
+12V
-12V
20
(23)
a
This line goes high when a connection exists
b
RFDCD (Also used for multi-node NET/ROM and ROSE)
