The IO Expander is connected to the CPU by Ribbon Cable, and to Redstone input and output by Bundled Cable. Only the back side will connect to bundled cable. The back side is facing away from the player when the IO Expander is placed. On the front side, there is a monochromatic red display; active output bits are lit.
The CPU can read and set Redstone signals for each individual cable color in the Bundled Cable attached to the IO Expander. Multiple IO Expanders can be used; in this case it becomes necessary to make sure that they have different Redbus IDs. If the same Redbus ID is used, generally only the closest IO Expander with that ID will be functional. To check or change the ID, one must shift-right-click with a Screwdriver or Sonic Screwdriver to reveal the Redbus dialog. The computer can read and write to only one I/O Expander at a time, but they maintain their output states while the computer uses a different one.
In order to send a signal to redstone cables, Ribbon Cable must be used to connect the CPU to an IO Expander. Bundled Cable must then lead from the IO Expander to any form of Insulated Wire. The different colours of wire are coded differently on the computer. These are shown in the table below.
Each of these numbers represents one binary bit out of 16. (They're called "bitflags".) Each of these 16 bits represents a color of wire. To get 2 or more colours on at once, you simply add the numbers together. For example, a signal through all the colours at once would be via the number 65535, as this is all 16 possibilities added together.
- For the actual coding, to stop all current signals and send a signal to a specific set of wires, type:
- [number] IOX!
- To stop all signals, type
- 0 IOX!
- To receive a signal from the IO Expander type:
- To send a signal without affecting all the other current signals type:
- [number] IOXSET
- To stop a signal without affecting other signals type:
- [number] IOXRST