SGI Indy on the Internet

A few assumptions about who will be using this guide

This guide was written from the perspective of someone who lives in the UK, has a telephone line in their room for their use only, is using an SGI Indy running IRIX 6.5.6, and whose ISP uses PPP (Point-to-Point Protocol). Further investigation has now been made into IRIX 6.2 and the sections added to this page; also this guide should apply to almost any SGI desktop workstation in the Indy, Indigo and Indigo2 range. No investigation has been made into SLIP or other methods of connecting to the internet so this document does not cover those methods. Give the document a quick scan first as I'd hate to be responsible for any disappointments or injuries. All pictures in this guide were taken with a blue backdrop for clarity of viewing only, and the soldering iron was not turned on while taking the pictures. Under no circumstances should you use a soldering iron where it may come into contact with flammable materials such as baggy clothing, long hair, paper or carpets etc.

Tip: Under IRIX 6.2 it will be necessary to edit several files. The easiest way to do this for a beginner is to use a GUI (Graphical User Interface) editor such as jot, which can be found in the Applications icon catalogue which is in Toolchest -> Find -> Applications. Or you could type in a shell window jot filename where filename is the complete path and filename of the file to be edited (eg jot /etc/uucp/Devices). A quick shortcut when done editing is to hold down Ctrl and press s then let go, then hold down Ctrl and press q then let go, which will save the file and exit jot.

Check out my FAQ for additional specific info.

There is also a text only version of this guide.


Where to start?
Before making your own modem cable
Making your own modem cable
Setting up the modem under IRIX 6.5.6
Setting up the modem under IRIX 6.2
Connecting to the Internet - IRIX 6.5.6, IRIX 6.2
Appendix A - Modems supported under IRIX 6.5.6
Appendix B - Soldering tips
Appendix C - Troubleshooting
Appendix D - Version of IRIX 6.2 & patches installed
What not to do!(Please read this first!)

Please email me with suggestions or requests and I'll see what I can do.

Where to start?

Firstly you need a modem, preferably one which is already supported by SGI under IRIX 6.x. See appendix A for a full list which is supported as standard under IRIX 6.5.6. In this document I use the word 'modem' to refer to my US Robotics 28,800 Sportster fax modem with V.34 and V.32bis, but other modems should follow a very similar setup procedure (especially under 6.5.6 with GUI!)


You'll need to either buy (expensive) or make (cheap!) a modem cable to go from your modem to one of the serial ports on the rear of the computer. To buy one you'll need to contact SGI or a reseller directly as I do not know of anyone else who will supply the correct cable spec. WARNING!! Do not be fooled into thinking that an Apple Mac modem cable will work just because it fits and the lights come on! This was one problem I encountered when I tried to get my modem to work (which I discovered later had a hardware fault).

Before making your own modem cable

Before venturing into the world of soldering and multicoloured wires, there are a few things you will need; to start with, make sure that the modem works! I cannot stress this enough as no matter how well you make the cable it just ain't gonna help if the modem is faulty! Test it on a friends computer first (PC, Mac or SGI, they all use the same modem commands) and then you'll know it's not your modem if it doesn't work!

some basic toolsAlso required will be some basic tools: two small flat bladed screwdrivers, some form of wire strippers (normal pliers will do), a sharp knife or wire cutters, a continuity tester (found on most multimeters), a decent soldering iron, at least 25 Watt, with a reasonably small tip and a damp sponge to clean the tip on, some resin core solder (quality solder makes a lot of difference, Multicore is good stuff to use) and some basic soldering skills. Maplins will be able to supply most of this stuff, and while you're there get yourself an Apple Mac modem cable which will be magically transformed into an SGI modem cable!

I recommend that the work is done on a solid table with a surface which doesn't matter if it gets scratched, such as a chopping board.

Making your own modem cable

Preparing the cable

Open the 25 way D-type serial end of the cable using the two screwdrivers by easing the tabs out and gently pulling the case halves apart, making sure not to loose the fixing bolts if you want to fix the cable to the modem at any time. To keep the casing from clipping back together carefully insert the second screwdriver into the case (so that's what it's for!) Be careful not to stab yourself when applying pressure. Keep all the casing parts together to one side until needed later.

Levering the coverLevering the coverLevering the coverThe cover opened

Testing for continuityUsing the multimeter, test the continuity of the wires to make sure you know which colour goes to which pin number on the 8-pin mini din plug, writing down what pin each coloured wire corresponds to; during my experience of two mac modem cables there was only one wire which was purple instead of grey. You can check your results against mine which are shown in a diagram later in this guide.

Desoldering the wiresDesolder all of the wires (except for the frame ground wire going to pin one), one at a time, from the 25 way D-type connector by heating the solder on the pin troughs and as soon as it has melted gently pull the wire away (or push it away with the soldering iron). CARE should be taken not to flick solder into your eyes when doing this as it can happen very easily! If you are worried about this then use some workshop or laboratory eye protectors. Tidy wires

Tidy up the wire ends so that they are neat and don't have too much bare wire showing (picture) otherwise there is a possibility of shorting pins when it is assembled (see appendix B - soldering tips) If you were careful in desoldering the wires they shouldn't need much tidying up.

Before reconnecting the wires make sure that the sheath is on the cable! I forgot about mine and look what happened.....

No grommet

Reconnecting the wires

Following the diagram, solder each wire in turn to the correct pin trough, applying extra solder to make a good connection. Make sure there is no loose solder and that the pins are tidy

NB: This diagram represents the actual plug looking at the pins, not the port itself. The 25-way D-type connector should have numbers next to each pin, but they are very small and difficult to see; as a general guide, looking at the 'back' of the port (where the wires connect to), the pins are laid out as follows: pin 1 is top right, pin 13 is top left, pin 14 is bottom right, and pin 25 is bottom left.

Indy serial cable (mini-din end)

Cable pinout assignments for Indy & Indigo2:
Pin (8 pin mini-din) Assignment Description Wire colour Pin (25-way)
1 DTR Data Terminal Ready Black 20
2 CTS Clear To Send Brown 5
3 TD Transmit Data Red 2
4 SG Signal Ground Orange 7
5 RD Receive Data Yellow 3
6 RTS Request To Send Green 4
7 DCD Data Carrier Detect Blue 8
8 SG Signal Ground Grey 7

This pinout applies to Indy, Indigo, Indigo2, Challenge S, Challenge M, Power Challenge M, and the MENET 4-Enet, 6-serial board (XT-FE-4TX-6A)

Finishing off

Place the 25-way D-type connector in the housing making sure to position the sheath and clamp in the correct positions, then insert the bolts and clip the casing together. If anything falls out of place it's a simple matter to re-open it and try again; it is worth getting it right as a sloppy job may cause difficulties later.

Connect the cable to the modem and to the computer serial port and you're ready to set up the modem.

Setting up the modem under IRIX 6.5.6

Under 6.5.6 it is a very easy matter to set up the modem using a GUI(Graphical User Interface) and selecting the relevant options. Go to System on the tool chest, then System Manager, Hardware and Devices, Add a Modem (in the serial devices section) Follow the steps through, giving the modem a name and selecting a serial port, then identify your modem from the list (if it is not there click on More Choices), choose the speed (for my 28,800 USR I chose 19200 as this is the highest speed supported by both the modem and the port, the Indy port speed goes from 19200 straight to 38400 which would give errors with the modem, so 19200 it is). If you chose the modem type correctly a string of relevant AT commands should already be in the Command String, best not to play with this at all! For regular internet access via an ISP, Dial Out is all that is needed.

If all has been successful then when you click on OK it should talk to the modem briefly and say that the installation was a success. You can test the modem manually at this point if you like by entering a command shell and typing cu n where n is a telephone number that you know works (beware that whoever picks up the phone will get a loud screeching noise in their ear!), you should hear the modem dialling if it has an internal speaker and the volume is sufficiently loud, and who/whatever picks up the phone.

Setting up the modem under IRIX 6.2

This is slightly more complex than the method used under IRIX 6.5.6 as there is no GUI, so you have to edit the relevant files and run various commands manually, but you should only have to do this once so it's not so bad!

The following information is a cut down version of what is in the online books so if you want to learn more you should look at IRIX Admin: Peripheral Devices, Terminals and Modems, Installing a Modem, but if you're like me and can't be bothered sifting through all the padding or you don't quite understand it, read on.

PPP and UUCP Utilities

Before going any further you will need the ppp and uucp utilities installed on your system, it would also be a good idea to have gone through the EZsetup utility from the visual login screen to set up a unique network address and machine name. The ppp and uucp utilities should be on the IRIX 6.2 installation media (actually on cdrom 1 of 2). To check if they are installed, type in a shell:

versions | grep uucp

the output should contain the following:

I eoe.sw.uucp         UUCP Utilities

If this is not present you will need to install it from your installation media. Otherwise continue!

Make sure you're logged in as root, and edit /etc/inittab to turn off the port you intend to use for your modem. The line you're looking for will look something like this:

t1:23:respawn:/sbin/getty -N ttyd1 co_9600 # port 1

Change respawn to off. If it is already off then leave it as it is. Write and exit the file (shortcut: Ctrl s, Ctrl q) then type telinit q in a shell and press return. The next step is to run the modem configuration script for your modem, the one that I used for my USRobotics Sportster 28800 was as follows:

/etc/uucp/fix-usr -o -m SPORT -s 19200 1

and this translates as follows:

When this script is run properly it sends a series of signals to the modem and attempts to reprogram the NVRAM in the modem so that it will talk to the SGI properly, it will show any dip switches that ought to be changed and keep you informed of what it is doing.

The next step is to configure the dial-out software. Edit the /etc/uucp/Devices file, adding the following lines to it:

ACU ttyf1 null 19200 212 x usr
Direct ttyd1 - 19200 direct
Direct ttyf1 - 19200 direct


See the help contained in /etc/uucp/Devices and the online books for a better description of what each field is for and other options. Write and exit the file before moving on.

Change the ownership of the devices file by typing in a shell:

chown uucp /dev/ttyf1

And that should be it! If all has gone well you should be able to use cu to dial a telephone number through your modem, but please be considerate if calling a phone that will be picked up by a human being. It is not mandatory to test the modem at this time as the next step, setting up PPP, shouldn't take long; it just depends how confident you are!

Connecting to the Internet

To begin with you must contact an ISP and ask to speak to their technical support staff (preferably a free phone number as this could take some time!) and kindly explain to them that you have a unix computer which you would like to connect to their server, and you need the following information (have a pen and paper ready):

The text in brackets is the information the guy gave me for my connection to Cable & Wireless's internet service provider, use them as examples only please. The guy I spoke to also gave me their gateway ( and proxy web server ( addresses but I found that I didn't need these. You might also explain that you will be using Netscape and Netscape Messenger if you intend to use them, it might make them feel more at home. If they start asking you about profiles for mail addresses, these liken to users on an SGI system so explain that each user has their own home directory with their own set of preference files for every program they use, and this is where each users mail preferences will be stored. Having profiles is Windows' way of getting round the problem of not having 'proper' user accounts.

Setting Up PPP Under IRIX 6.5.6

Open up the System manager if it is not already open, go to Networking and Connectivity, Add an Outgoing PPP Connection (in the PPP management section) and enter the dial-up number, login name, login password, Primary DNS, Secondary DNS, Authentication protocol (PAP & CHAP on my system) in the relevant boxes. Set local and remote IP address to 0 (the ISP will assign these when you log on)

If the ISP offers you several e-mail addresses the way to organise these is to fill in the e-mail usernames differently for different users on your computer, eg. if you have e-mail addresses that go mailuser1 mailuser2 mailuser3, set up user accounts on your computer with the Netscape preferences incorporating the relevant mail username for each one. As an example of this my setup is such that when I log into my Indy as jonathan, my mail username is mail00; if I set up another user account on my Indy I could have the same mail username or I could have mail01 as the mail username in Netscape preferences.

Setting Up PPP Under IRIX 6.2

As with the modem setup procedure, this is a matter of editing files and running shell commands. Here is where the parts come together and begin to make sense.

Again, for a more detailed guide and description of what things do, see the online book IRIX Admin: Networking and Mail, SLIP and PPP.

Edit the /etc/uucp/Systems file, adding a line similar to the following:

cw Any ACU 19200 08453088860 "" @\r\c


Write and exit the file.

Edit /etc/ppp.conf so that it contains the information required to log into your ISPs computer. Your ISP may have specific requirements, so make your own additions/removals as required to the example below;

cw send_name=loginname

loginname and loginpassword will either be supplied by your ISP or created yourself if you previously made an account with an ISP online.

Finally, add the Domain Name Server address(es) given to you by your ISP to /etc/resolv.conf (you may need to create this file) so that it looks something like this:


Write and exit the file.

Restart the system!

To start your ppp connection, make sure the modem is switched on and enter in a shell:

ppp -r cw

(cw is the name you gave the ppp connection earlier)

and the modem should begin dialling. Within a few seconds you should hear some warbling noises as the modems talk to each other and the SD/TR lights will flash briefly a few times then go out, and the RD, CS, and ARQ lights should stay lit. You should see output from ppp similar to the following:

ppp[1045]: cw IPCP: ready to

The IP addresses here are dynamic so they change each time I log on to their server. If all is well no more messages should appear. See the Appendix C - Troubleshooting if your connection fails or times out after about a minute.

To use Netscape and Netscape mail you will need to insert the mail/news server addresses and your email address etc into Netscape preferences, then exit and restart Netscape.

Important! In order to terminate the session, I have found the only way is to kill the process (in the square brackets after ppp, shown above) so to do this type in a spare shell:

kill 1045

where 1045 is the process number (displayed after "ppp" in square brackets), and ppp should terminate the call and return an exit message similar to "received signal 15" then quit, returning to the shell prompt. The modem should have just the CS light lit (or whatever lights were lit before the connection began).

Appendix A - Modems supported under IRIX 6.5.6

This is a very long list! Download the text file here.

Appendix B - Soldering tips

Tidying up wire ends

To effectively do this it is recommended to cut the ends off all the wires so that they are all the same length and strip approximately 2mm only of the sheathing off, give the bare wire a quick twist then tin it.


Tinning is a term which refers to making solder stick to a metal surface or object such as a wire or piece of metal. To tin, apply heat to the object such that when solder is pushed against it the solder begins to melt and adhere to the surface. The closer to the soldering iron the solder is pushed the better, as the heat is hottest there.

Tinning wire ends

To tin a wire end, first it should be clean and twisted; hold the soldering iron so that it is heating the bare wire and gently push the solder onto the wire AND the soldering iron so that it melts and 'seeps' into the twisted wire. Remove the heat as soon as it has gone into most of the bare twisted wire, checking on the reverse side as well. If more solder is required simply repeat the process.

What not to do!

Do NOT leave the soldering iron on the floor or balanced on a table edge! This can lead to burnt carpets or arms/legs/hands. A proper soldering iron station should be used which are not expensive at all (usually comes with a sponge too)

Appendix C - Troubleshooting

So it all went tits up? Well don't fret, it happened to me lots of times! There are many things you can check, so check this list:

The files that need to be changed generally have some good help and guidelines in them, as well as the online books. If you feel you are missing some information then check SGIs techpubs site at If you are still stuck you could always try the newsgroups on SGI and IRIX Admin, there's usually someone there who can help.

Appendix C - Version of IRIX 6.2 & patches installed

When this guide was made the following version of IRIX 6.2 was installed:

IRIX 6.2 with IMPACT 10000

Plus these patches.

The chkconfig list looked like this.

It is recommended that you have these patches and version installed if possible as they improve a lot of the functionality dramatically and help stabilize the system.

The above procedure has also been tried with a fresh install of IRIX 6.2 with no patches and it worked fine. On a 1GB disk there was approximately 500MB free with a default installation plus the uucp utilities and ppp software.

This document and all pictures (except for port diagram) were created by Jonathan Mortimer, year 2000. Last updated 16th March 2001

I make no claims to the appropriateness or correctness of the information contained within this document, and any injuries or damage caused by following this advice is entirely not my fault.

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