Joystick connection (C64/Amiga)

[aMIGA_dUDE]

Having a debate with a friend about joysticks on the C64 and Amiga. To keep it short this what it all about.

It is possible for software to know if there Joystick connect or not. What is being claimed that C64/Amiga were able to detect if joystick was connected or disconnected.
So lets say you where playing a 2 player game. Both players where using there own joystick's and mid way thought the game 1 of the plays joysticks got disconnect from the computer. The C64/Amiga was able to detect that 1 of plays joystick got disconnected. The software would know this had happen as such it would pause the game.

The only game could think of that happen on in was Xenon 2.

[tone007]

I was pretty sure those digital joysticks are just a bunch of momentary switches wired directly to the pins of the connector, and at rest all connections are open, so I don't see how a joystick could be detected.

[Zac67]

There's no way to detect a joystick if it's not used.

An Atari style joystick consists of five switches - four directional, one fire button (possibly two). Each switch connects the according sense line to ground when activated. Without moving the stick or pressing the button all sense lines are pulled high and there's no difference between an inactive stick and none present.

[save2600]

Weird scenario, unless you're talking about the joystick accidentally coming unplugged because someone either tripped on the cord or got a little too excited during gameplay.

Perhaps your friend is confusing a "smart" Amiga joystick port with the disk drives? Yep, Amiga's know when a 3-1/2" disk has been inserted or removed  :lol:

A possibility for a smart joystick port would be if the joystick had circuitry inside that was powered by or looped the +5v line back into the computer. The software to sense that though would either be built into Kickstart or through each piece of software individually. You can see where this concept would be pretty frivoulous in practice as it's all too obvious to the user whether something is plugged in or not.

-edit-

Good one lsmart! lol

[lsmart]

In a game it is farly easy to detect an unplugged joystick: The player doesn´t move ;-)

[runequester]

Before I got some switch boxes, I've unplugged and swapped out joystick and mice plenty of time and I can't say I've ever noticed a game react to that

[Franko]

As everyone else has said, there is nothing in a standard joystick that would enable software to detect on either the C64 or Amiga...

Just played Xenon 2 on the miggy and nope there is no game pause if you unplug the joystick...

So c'mon spill the beans which one of you claimed it would in this wee debate you or your friend...

[motrucker]

Before I got some switch boxes, I've unplugged and swapped out joystick and mice plenty of time and I can't say I've ever noticed a game react to that

You are playing with fire. That's one of the best ways to blow out a CIA chip!

[runequester]

You are playing with fire. That's one of the best ways to blow out a CIA chip!

Thats why I got a pair of switch thingies to have 2 devices plugged into one port

[Franko]

Disconnecting a joystick while the miggie is on is perfectly safe as long as you don't have any of the fire buttons or directional switches pressed on when doing so...

[psxphill]

You are playing with fire. That's one of the best ways to blow out a CIA chip!

the biggest problem is when you touch all the pins with your finger trying to find the socket when plugging the joystick in.

[kedawa]

Disconnecting a joystick while the miggie is on is perfectly safe as long as you don't have any of the fire buttons or directional switches pressed on when doing so...

That wouldn't do any harm either.  The joystick is either connected or it's not.  In either case, pressing the buttons and moving the joystick won't cause any harm.  The 5V used in the port isn't enough to arc or cause back EMF, so the actual process of disconnection doesn't present any special danger.

[gertsy]

the biggest problem is when you touch all the pins with your finger trying to find the socket when plugging the joystick in.

No, unless your finger's wet, or you've had it in your nose or ear. The biggest problem is when you fumble around trying to plug in a metal rimmed plug (like some mouse plugs) and the rim shorts pin 7 to the joystick port skirt.  Apart from that you can plug and unplug a plastic joystick plug while the Amiga is on without any danger to it.
The biggest anoyance is the recessed joystick ports, you cant see them unless you have a go go gadget neck.

BTW. If you had a special joystick made up it could be detected by providing a resistance on pin 5, the lightpen button / X-Pot connection.  But normal digital joysticks; no go on a detection there.

[Zac67]

That's right - there are two perils when 'hot' plugging devices:
- shorting powered pins to ground (causing a fuse or track to burn) or an I/O pin that can't cope with it (destroying some active component)
- static electricity: even when not noticable to humans, static buildup (of a non-earthed device or body) of a few hundred to several thousand!(!) volts can instantly destroy electronics

While the Amiga's joystick/mouse ports are explicitly hardened against the latter danger (see manual) there still is some danger, so handle with care!

[gertsy]

That's right - there are two perils when 'hot' plugging devices:
- shorting powered pins to ground (causing a fuse or track to burn) or an I/O pin that can't cope with it (destroying some active component)
- static electricity: even when not noticable to humans, static buildup (of a non-earthed device or body) of a few hundred to several thousand!(!) volts can instantly destroy electronics

While the Amiga's joystick/mouse ports are explicitly hardened against the latter danger (see manual) there still is some danger, so handle with care!

This guy goes through PCs like you wouldn't believe.
http://superherouniverse.com/art/showphoto.php/photo/16795/ppuser/890