Connecting to your SGI
via Serial Cable

 General Information


Sometimes it may be neccessary to access your SGI without keyboard, mouse and monitor. Many servers, like the SGI Origin even don't have a graphic adaptor installed, so this is your only chance for installing IRIX on that machine. This page describes how to connect to a machine via a serial cable.

Using a Serial Cable

Connecting a PC or another workstation to your SGI via a serial link is really straightforward. You only need a Null-Modem cable and connect it to your SGI and to your terminal (e.g. another SGI or a PC or whatever you like). Note that so called "Laplink" cables don't work, they will just cause you problems - you need a true null-modem connection.

Also note that some older SGIs like my Personal Iris 4D/25 already have a crossed connection - the connectors are female 9 pin connectors insread of the standard male connectors. Here you do not need a Null-Modem cable

Your terminal settings should be as follows:

Speed  9600baud 
Data bits 8
Parity None
Stop bits 1
Flowcontrol  None

The short abbreviation for these settings is 9600 8N1 and no flowcontrol. If possible, emulate a VT-100 terminal (almost every terminal does). And very important: Do not connect a keyboard to the SGI machine. This last requirement is neccessary, because with a keyboard connected to your machine, the SGI won't jump into serial mode at boot time.

There is also the possibility of forcing your SGI to boot in serial mode by changing the environment variable console within the PROM. This variable has the following valid values:

Value Meaning
g or G
g0, g1, g2
If console is set to g or G, the console is assumed to be the graphics display. On some systems with multiple graphics adapters, setting console to g0 (identical to g), g1, or g2 can be used to select alternate graphics displays.
d or d2 If console is set to d, the console is assumed to be a terminal connected to the first serial port. In addition, some systems also accept d2 for a terminal connected to second serial port.

Forcing a serial connect can be done by typing

setenv console d

and the default behaviour is restored by typing

setenv console g

Booting my Personal Iris 4D/25 then gives this screen:

Console DUART test                      PASSED
Memory walking bit test                 PASSED
Memory address uniqueness test          PASSED
Interrupt mask registers test           PASSED
Graphics subsystem test                 PASSED

System Maintenance Menu

1) Start System
2) Install System Software
3) Run Diagnostics
4) Recover System
5) Enter Command Monitor