Brilliant! A unique way around every problem.
Jeff Birt
-----Original Message-----
From: M100 <m100-boun...@lists.bitchin100.com> On Behalf Of Jim Anderson
Sent: Monday, January 4, 2021 1:55 PM
To: m...@bitchin100.com
Subject: Re: [M100] Joystick for the M100
> -----Original Message-----
> For input, there are only 2 signals, BUSY and BUSY_N. Each of these
> can be read independenty.
As I recall, the way it worked was that the five switches (directional
switches and fire) were wired to the first five output bits, and the common
return from all five switches was wired to BUSY. To poll the joystick you'd
cycle through outputting ASCII 1, 2, 4, 8, and 16, and read BUSY each time.
Whichever bits resulted in assertion of BUSY meant that switch was currently
closed.
jim
