RCM - RETRO COMPUTER MUSEUM

GENERAL => NEW MEMBERS - SIGN IN HERE PLEASE => Topic started by: dan on December 06, 2010, 08:38:52 AM

Title: Hello everybody
Post by: dan on December 06, 2010, 08:38:52 AM
Hi Everybody,

Just introducing myself - I'm based on the Isle of Wight and I am interested in any old Acorn hardware, particularly the 8-bit stuff. I stumbled across RCM while looking for ways of interfacing a PC Gameport joystick to the BBC Micro's analogue port (if anybody can help with this, please let me know).

All the best,

-dan
Title: Re: Hello everybody
Post by: Panther on December 06, 2010, 08:47:52 AM
Hiya Dan,

Not been to the IOW for a while, used to go all the time !!

Welcome to RCM  :)

I stumbled across RCM while looking for ways of interfacing a PC Gameport joystick to the BBC Micro's analogue port (if anybody can help with this, please let me know).


Over to Phu for this one methinks !!
Title: Re: Hello everybody
Post by: Phu on December 06, 2010, 03:04:19 PM
A genuine analogue stick can be made to work with a BBC Micro, as they operate on the same principle.

If you dig out the analogue port pinout from the User Guide, and look up a PC game port pinout on the internet you can see the pin translations needed.

Normally PC Game ports string the resistors between +5V and ground. On the BBC, you want VRef (which is the absolute high voltage reference for the A/D conversion) rather than the +5V supply on the port. Otherwise it should be pretty simple.

Interfacing digital sticks is a bit harder, as there seems to be some quirk of the A/D circuit that makes normal circuitry not work right. Something that is giving me a right pain in the arse at the moment.

By the way, I'm just up the country from you in Portsmouth :)

-- Richard