Using the Indigo Keyboard
with a Personal Iris

 General Information

Introduction

When I got my Personal Iris 4D/25, I had no keyboard for this machine. Unfortunately it needs a special keyboard with a DB9 male connector - it's not just a different connector, the communication protocol of the keyboard also differs from standard PS/2 or AT keyobards. But luckily I own an SGI Indigo 1 including a keyboard. This keyboard uses the same protocol as the one of many other old SGI machines, but has a different connector (it has a Mini-DIN-6 connector like a PS/2 keyboard). So I had to build an adaptor.

Pinouts of the Indigo Keyboard

Pin Description
1 K_TXD/K_RXD
2 M_TXD/M_RXD
3 Ground
4 +12
5 K_RXD/K_TXD
6 -12

Pinouts of the Personal Iris Keyboard

Pin Description
1 Ground
2 K_TXD/K_RXD
3 Ground
4 -12
5 M_TXD/M_RXD
6 Ground
7 +12
8 K_RXD/K_TXD
9 Ground

Pinout of even older SGIs

Pin Description
1 Ground
2 Ground
3 Ground
4 K_RXD/K_TXD
5 K_TXD/K_RXD
6 N/C
7 +12
8 +12
9 +12
10 M_TXD/M_RXD
11 Reserved
12 Reserved
13 N/C
14 N/C
15 -12

 

Pinout of Converter Cable

Knowing the pinouts of the connectors, an adaptor cable can be assembled using 6 wires, one DB9 male connector and one Mini DIN6 female connector with the following table:

 

DB9 Pin Description DIN6 Pin
1 Ground NC
2 K_TXD/K_RXD 1
3 Ground NC
4 -12 6
5 M_TXD/M_RXD 2
6 Ground 3
7 +12 4
8 K_RXD/K_TXD 5
9 Ground NC
My converter cable looks this simple:

If you even don't have an Indigo Keyboard

Then there is still a chance: There exists a tutorial how to build a cnoverter for the SGI Indigo to plug in standard PS/2 keyboards and mice. But this one is far trickier.

 Links