USEREK5X@mts.rpi.EDU (11/10/87)
I also would like some joystick I/O info. As far as I know, tying a pin to +5v will signal a 'joystick' up, down, left, right, etc. This means that impossible joystick movements like up-down are also possible. I think there is a listing in the Atari manual, but it is always possible to get a listing by just printing the memory locations of a joystick port and connecting different pins to the 5 volt pin to see what value is printed. Don't connect the 5 volt pin to ground... Bryant
saulnier@cg-atla.UUCP (Jim Saulnier X7097) (11/10/87)
The joystick data lines are ACTIVE LOW. If nothing is connected
to these ports, you will read $FF from the joystick register.
I would not advise connecting +5v to ANY of these lines. I'm
not sure if any damage would result, but it's not a good idea
anyway. The Atari Hardware manual has the pinout for these
ports. I usually read directly from the regiter rather than
the shadow locations. In my 130XE, both data ports can be
read from the same register ($D300 I think), with port 0
being the lower nibble and port 1 the upper nibble.
Anyway, if you want to find the data lines, connect GND to
the different pins and read the register or shadow.
Better yet, at your request, I will post the pinout for
the port and requirements for reading/writing this port.
--
Jim Saulnier
...!{decvax,ima,ism780c,ulowell,cgeuro,cg-f}!cg-atla!saulnier
"Wow, it never did THAT before."