Re: Unindentifiable motherboard port (II Plus clone)

[Rubywand <rubywand@swbell.net>]

Michael Black writes ...
> 
> On 1 Dec 1998, Dave Althoff wrote:
> [stuff deleted
> > Perhaps those are (were) ports for switch-type joysticks?  Atari 2600
> > joysticks have female DB-9 connectors on them, which would necessarily
> > mate to male DB-9 connectors...
> >
> Someone, I think Mitchell, mentioned plugging Atari joysticks in and not
> only did it not do anything, but it caused problems to the rest of the
> system.
> 
> There's no 16pin DIP socket for I/O, so these have to be for normal I/O.
> 
> One pin on each of the I/O sockets goes through an RC network to an input
> pin of the 558 quad timer.
> 
> I guess I should just trace the pinouts (I located my Apple II manual with
> the schematic of the original) and post the results.  Whether there is a
> standard pinout for this non-standard (for the Apple II) I/O connector is
> another matter.
> 

     Perhaps what you have is a C-64 compatible game I/O port. The
standard Commodore-64 Game port has a male 9-pin DIN socket.

     Although C-64 joysticks are of the simple "switcher" type which
connect to Game port switch inputs, the C-64 Game port also includes X
and Y analog "paddle" inputs. These are at pin 9 (X) and pin 5 (Y).
Evidently, these are used by drawing pads (like the C-64 version of
Koala) and other peripherals with analog outputs.

     A check of the C-64 diagram shows that the capacitor part of the
expected analog R/C circuit is 1000 pF in each case and the caps go to
ground just as they do in the Apple II. In fact, the C-64 "paddle"
inputs look very much like the Apple II joystick inputs.

    _IF_ the port is C-64 compatible, the pinout info shown below may
help. (The connections shown are a fairly good bet for using an Apple II
joystick.)


      C-64 Game Port           Apple II Joystick
     (9-pin male DIN)         (need 9-pin DIN male->female converter) 

        1 -  JSw0*
        2 <- JSw1*             2nd Button**  -> 1
        3 -  JSw2*
        4 -  JSw3*
        5 <- Pot Y             PDL1 (y-axis) -> 8
        6 <- Button            Fire Button** -> 7
        7 <- +5V line          +5V           -> 2
        8 <- GND               GND           -> 3
        9 <- Pot X             PDL0 (x-axis) -> 5


 * These are the regular C-64 'switcher-type' joystick switch inputs.
 
** The joystick button assignments are guesses based upon Koala Pad
   wiring.



Rubywand