The bcr port input triggers a cpu interrupt. One could imagine bit banging a byte of data with bits indicating joystick status.
On interrupt you could then poll the bcr input and implement a kind of software uart to read the byte. The joystick would need some kind of adapter to convert the switch status into a byte that fires at a known rate. Kind of a fun idea. Trick would be to send the byte only when the status changes. So two pieces 1. A hardware joystick adapter 2. A bcr port driver to read the joystick status as a byte of data, updated on change of status On Tuesday, September 23, 2025, Scott McDonnell <[email protected]> wrote: > I am back to thinking about a joystick for the Model 100. I have a > specific reason in mind and even a specific joystick. > > My intent is to target the Atari/Commodore 64 digital joystick interface > mainly because my inspiration is the Suncom Icontroller which mounts to the > side of the machine. > > This interface is a series of 5 discrete switches to control direction and > a fire button. Very basic. > > While the parallel port would have been ideal for something like this, it > is not bidirectional and offers only two inputs. > > The serial port provides 3 inputs; still not enough > > While some multiplexing strategies might allow this to work, both of those > ports are also often used for other important purposes. > > So I started thinking about the barcode port. It only has one input, but > the joystick could be encoded into a serial stream. Maybe even using the > original barcode drivers. I don't know the specifics of the BCR > implementation here, but often they are just keyboard wedges. > > Any thoughts on this or a better solution? > > >
