This repository provides a simple driver for a 9-pin joystick that can be connected to a parallel port. I built this for the A5000 so that I could play Elite with the same joystick I'd used on the BBC.
The module provides only the 8bit interface, but as a switched joystick, this is all that is necessary.
The driver builds automatically on pushes using the RISC OS Build service.
To manually build the module, push the code to the server using the riscos-build-online tool. For example:
curl -s -L -o riscos-build-online https://github.com/gerph/robuild-client/releases/download/v0.05/riscos-build-online && chmod +x riscos-build-online
zip -q9r /tmp/source-archive.zip * .robuild.yaml
./riscos-build-online -i /tmp/source-archive.zip -a off -t 60 -o archive
This will produce a binary called archive,a91 which is a RISC OS zip archive containing the module.
This is not really an interface, just a one-to-one relationship for the connectors.
You require a 9-pin joystick like this :
1 2 3 4 5
6 7 8 9
and a printer lead. The printer lead must have the printer end removed so that all the wires are accessable.
You may need to open the computer end to note the colours of the leads so that you can connect the correct wire to each hole.
At the computer end the first wire on my lead is brown, then red, orange, pink. The wires are labelled (with my colours) :
| Pin | Colour | Name | Direction |
|---|---|---|---|
| 1 | Brown | Strobe | I/O |
| 2 | Red | D0 | I/O |
| 3 | Orange | D1 | I/O |
| 4 | Pink | D2 | I/O |
| 5 | Yellow | D3 | I/O |
| 6 | Dark Green | D4 | I/O |
| 7 | Cyan | D5 | I/O |
| 8 | Blue | D6 | I/O |
| 9 | Blue (Stripe) | D7 | I/O |
| 10 | Purple | Ack | I |
| 11 | Grey | Busy | I |
| 12 | White | Paper Error | I |
| 13 | Black | Select | I |
| 14 | Brown (Stripe) | Auto feed | O |
| 15 | Red (Stripe) | Error | I |
| 16 | Orange (Stripe) | Reset | O |
| 17 | Green (Stripe) | Select In | O |
| 18 | Black (Stripe) | Ground | N/A |
Directions relative to computer.
Connect the following :
| Computer | 9-pin |
|---|---|
| 2 | 2 |
| 3 | 3 |
| 4 | 4 |
| 5 | 5 |
| 16 | 7 |
| 6 | 9 |
So, if you have the same lead as me the lead should read (left to right) :
- Nothing, Red, Orange, Pink, Yellow
- Nothing, Orange (Stripe), Nothing, Green
And connect 12, 13, and 15 to 14 in the Computer lead. The reason for this is to allow some simple testing of the parallel port to see if the Joystick is connected or not. What should happen is that when the AutoFeed line is toggled, so should the PaperError, Select, and Error return lines be toggled.
I have used bits D0-D4 to mark up, down, left, right and fire, and used Reset to provide the power for the joystick. Therefore, reset must always be kept high. As the parallel port retains settings and the joystick never clears set bits after each read the joystick should be cleared. To be exact, the value read will be that of the directions moved /since the last clear/ and it is possible that all directions could be set. To alleviate this the read code might be placed on an interrupt, but I'm not bothered, as most games read the joystick regularly.