Whats the deal with controller ports?!

[VicViper]

Seriously, why can no two games agree on what port to use? why do so many games insist on using port 2? is there a technical reason?

[carlsson]

Partly yes. The keyboard and joystick port #1 share some lines of the CIA chip so there could be misreadings of the joystick as keyboard input. Thus many games prefer to use port #2 as it doesn't interfer with anyhthing. Other games managed to get around the misreadings or just didn't care, and were programmed for port #1 instead.

 

Even if Commodore didn't want to reroute the ports, they could easily have gotten away with it by just renaming the ports on the outside so port #1 is closest to the power connector. It might've made more developers use the same port.

 

Actually once you start to PEEK around in the memory map, port #2 is at address 56320 and port #1 is at address 56321 so something went wrong with the labeling on the outside, methinks.

Edited August 19, 2017 by carlsson

[VicViper]

As always, Carlsson comes through. Thanks!

Edited August 20, 2017 by VicViper

[landgraf]

Actually both ports interfere with the keybord, the way a joystick in port 2 modifies the keyboard readout is just a bit more subtle(*).

 

What really puzzles me is that nearly no game could be arsed to simply poll boths ports in single player mode as this is quite easy to do code-wise - yet Uridium is the only game I know that does that.

 

(*) if you scan the keys the way the kernal rom routine does it - custom made scanners may "reverse" the scan direction and thereby also reverse how each joyport interferes with the results.

[+save2600]

Seems kind of trivial on the surface, but ends up being one of the most aggravating aspects of gaming on the C64. I share your pain VicViper!

[motrucker]

You could use a joystick switcher, to change the active port at the touch of a button - either from SkydivinGirl or COREi64.

 

http://www.lemon64.com/forum/viewtopic.php?t=59117&postdays=0&postorder=asc&start=165

 

 

[danny_galaga]

I'm just putting the finishing touches on another controller, so my solution will be the time honoured method of just leaving controllers in both ports

[Nateo]

You could use a joystick switcher, to change the active port at the touch of a button - either from SkydivinGirl or COREi64.

 

http://www.lemon64.com/forum/viewtopic.php?t=59117&postdays=0&postorder=asc&start=165

 

 

I'll second the joystick switcher. It's so dang convenient.

[7800fan]

Yes and safe with controller that draws power like Hot Stuff joystick with built in rapid fire. Plugging and unplugging risk blowing CIA but the switcher allows me to switch port without unplugging.

[+remowilliams]

The joystick switcher is a must have as far as I'm concerned. Bonus points that you can print your own case for it

 

 

[CRTGAMER]

On my 128D, I just leave a Wico plugged in each port. Grab the stick that works for each game.

Edited September 3, 2017 by CRTGAMER

[The Mr. Video]

Partly yes. The keyboard and joystick port #1 share some lines of the CIA chip so there could be misreadings of the joystick as keyboard input. Thus many games prefer to use port #2 as it doesn't interfer with anyhthing. Other games managed to get around the misreadings or just didn't care, and were programmed for port #1 instead.

 

Even if Commodore didn't want to reroute the ports, they could easily have gotten away with it by just renaming the ports on the outside so port #1 is closest to the power connector. It might've made more developers use the same port.

 

Actually once you start to PEEK around in the memory map, port #2 is at address 56320 and port #1 is at address 56321 so something went wrong with the labeling on the outside, methinks.

Always wondered about that. Also I remember that moving a joystick in port 1 while in BASIC will type in different characters, as if you typed them in using the keyboard.

[White Flame]

Always wondered about that. Also I remember that moving a joystick in port 1 while in BASIC will type in different characters, as if you typed them in using the keyboard.

 

The inverse is also true, in that you can press the same affected keys (Ctrl, ←, 1, 2, and Space) to spoof a joystick from port 1.

[eightbit]

I just keep two joysticks plugged in. One doesn't work for a game I grab the other. Been doing that since the 80's