# SUN LX/Classic/SS4/5/10/20 Serial Port

This port is located in modern SUN Sparcs such as SUN LX/Classic/SS4/5/10/20 and has both serial ports (A/B) in the same connector. Simply plugging in a regular serial cable in results in accessing port A.

(at the computer)

25 PIN D-SUB FEMALE at the computer.

Pin | Name | Port | Dir | Description
--- | --- | --- | --- | ---
2 | TXD | A |  | Transmit Data
3 | RXD | A |  | Receive Data
4 | RTS | A |  | Request to Send
5 | CTS | A |  | Clear to Send
6 | DSR | A |  | Data Set Ready
7 | GND | - | - | System Ground
8 | CD | A |  | Carrier Detect
11 | DTR | B |  | Data Terminal Ready
12 | CD | B |  | Carrier Detect
13 | CTS | B |  | Clear to Send
14 | TXD | B |  | Transmit Data
15 | TC | A |  | Transmit Clock from DCE, usually not used
16 | RXD | B |  | Receive Data
17 | RC | A |  | Receive Clock from DCE, usually not used
18 | TC | B |  | Transmit Clock from DCE, usually not used
19 | RTS | B |  | Request to Send
20 | DTR | A |  | Data Terminal Ready
21 | TCO | A |  | Transmit Clock from DTE, usually not used.
25 | TCO | B |  | Transmit Clock from DTE, usually not used.

Note: Direction is DTE (Computer) relative DCE (Modem).
Note: Do not connect SHIELD(1) to GND(7).

Contributor: Niklas Edmundsson

Source:
SUN Field Engineer Handbook, VolumeII, 12/15/93

Copyright © The Hardware Book Team 1996-2001.
May be copied and redistributed, partially or in whole, as appropriate.
Document last modified: 2001-06-07