Atari Joystick to Apple II's "Atari Joyport" converter
Lukazi
Joysticks on Apple II using "Atari Joyport"
Thanks for all the help. It got me going in the right direction.
Now that I have completed it you can see the Atari Joystick to Apple
II's "Atari Joyport" converter here in my blog:
http://lukazi.blogspot.com/2009/04/game-controller-atari-joysticks.html
The way in which the Joyport works it sets PB0, PB1 and PB2 to the on
state when the joystick is not in use. Since PB0 and PB1 are tied to
the Open-Apple and Closed-Apple keys this causes a problem during
reboot ie you get a self test instead. I would be interest to hear if
anyone has a better work around than the ones I came up with.
Cheers,
Alex.
Dutch
On 2009-04-29 20:35:12 -0600, Lukazi <luk...@hotmail.com> said:
<snip>
> Now that I have completed it you can see the Atari Joystick to Apple
> II's "Atari Joyport" converter here in my blog:
> http://lukazi.blogspot.com/2009/04/game-controller-atari-joysticks.html
< snip>
> Cheers,
>
>
> Alex.
This is pretty cool. I built this over the weekend from the schematic
on the blog, and wrote a quickie program to test the logic. I noticed
some additional diodes have been added to the circuit. Mine seems to
work fine without them. What benefit does this add, and is D3
backwards?
I recall some joyport games, but its been a really long time. Anybody
remember any titles?
Dutch
Michael J. Mahon
> To: Lukazi
>
> On 2009-04-29 20:35:12 -0600, Lukazi <luk...@hotmail.com> said:
>
> <snip>
>
>> Now that I have completed it you can see the Atari Joystick to Apple
>> II's "Atari Joyport" converter here in my blog:
>> http://lukazi.blogspot.com/2009/04/game-controller-atari-joysticks.html
>
> < snip>
>
>> Cheers,
>>
>>
>> Alex.
>
> This is pretty cool. I built this over the weekend from the schematic
> on the blog, and wrote a quickie program to test the logic. I noticed
> some additional diodes have been added to the circuit. Mine seems to
> work fine without them. What benefit does this add, and is D3 backwards?
No mistake. The diodes protect the mux outputs from being shorted by
the simultaneous actuation of the Apple keys or the Shift key (if the
shift key mod is installed).
The PB2 diode is reversed because the Shift key grounds the PB2 input,
while the Apple keys connect PB0 and PB1 to +5v. PB0 and PB1 are
pulled down by 470 ohm resistors in the keyboard, while the shift key
mod pulls PB2 up.
-michael
******** Note new website URL ********
NadaNet and AppleCrate II for Apple II parallel computing!
Home page: http://home.comcast.net/~mjmahon/
"The wastebasket is our most important design
tool--and it's seriously underused."
Nick Westgate
> I recall some joyport games, but its been a really long time. Anybody
> remember any titles?
Some Sirius titles supported it - I recall "Borg".
(Not a great game but I have a strange fondness for it.)
Cheers,
Nick.
Lukazi
with it. I will do that next week. Very busy.
The diodes are there thanks to Michael pointing out my mistake.
I'm going to update the Blog with more information on the reboot
problem. Just some more details I have come across since building the
converter. Basically no easy fix. Sirus Joyport had the same problem
ie Apple IIe introduced the self test which conflicted with the
Joyport operation.
I am starting to go though my software list. Spy's Demise and
Boulderdash is what I have started playing again. Boulderdash (for me)
is a lot easier to play using the Atari Joysticks.
I may post a short list to my blog.
Cheers,
Alex.
Dutch
<snip>
> The PB2 diode is reversed because the Shift key grounds the PB2 input,
> while the Apple keys connect PB0 and PB1 to +5v. PB0 and PB1 are
> pulled down by 470 ohm resistors in the keyboard, while the shift key
> mod pulls PB2 up.
>
> -michael
<snip>
Good point! I had forgotten about the shift mod on the iie. After
reviewing the schematic the the game connector and it became clearer.
Thanks for the heads up.
Dutch