| I've tested several PS/2 splitter wiring setups and none of them worked, here's what did work for my I-Opener. I verified this wiring works, twice.
First, let's get the pin numbering straight:
PS/2 Connector
Male, plug into IO
------------------
5- o|o -6
3- o o -4
1- o o -2
PS/2 Connector
Female, Mouse or
Keyboard plugs into it
----------------------
6- o|o -5
4- o o -3
2- o o -1
Wiring:
The basic idea is that a typical PS/2 device doesn't use pins #2 & #6, so the IO uses these to allow a second device. Pin 2 is a second data input, pin 6 is a second clock input.
Male PS/2 | Pin | Mouse PS/2 | Keyb PS/2
(To IO) Pin | Function | Conn Female | Conn Female
---------------------------------------------------
1 |KB Data | n/c |1
2 |Mouse Data | 1 |2
3 |Ground | 3 |3
4 |+5 volts | 4 |4
5 |KB Clock | n/c |5
6 |Mouse Clock| 5 |6
To put another way:
IO connector pin #1 goes to Keyboard connector pin 1.
IO connector pin #2 goes to Mouse connector pin 1, and Keyboard connector pin 2.
IO connector pin #3 goes to Mouse connector pin 3, and Keyboard connector pin 3.
IO connector pin #4 goes to Mouse connector pin 4, and Keyboard connector pin 4.
IO connector pin #5 goes to Keyboard connector pin 5.
IO connector pin #6 goes to Mouse connector pin 5, and Keyboard connector pin 6.
I'm fairly certain you don't *need* to wire through pins #2 and #6 on the keyboard, but it works for me and doesn't cause any harm.
Don't forget to wire all the shielding (bare wires) together for all your connectors. | 
