Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!cse!desimone
From: desimone@cse.uta.edu (David DeSimone)
Newsgroups: comp.sys.cbm
Subject: Re: Joyless Joyport
Message-ID: <1991May7.185459.2433@cse.uta.edu>
Date: 7 May 91 18:54:59 GMT
References: <4186@meaddata.meaddata.com> <1984@ahds.UUCP>
Organization: Computer Science Engineering Univ. of Texas at Arlington
Lines: 27

In article <4186@meaddata.meaddata.com>, johnt@meaddata.com (John Townsend) writes:
> A friend of mine, who is a big C64/128 fan, has a C64 with a sick joyport.
> The JOY1 port works fine, but when a working joystick is plugged into JOY2,
> it will go left and fire, but not go up, down, or right.  The contacts with
> the port appear to be fine.  Do you have any idea what the problem could be?

The most common cause of this is a frotzed 6526 CIA chip.  This is an
incredibly common occurence, since Commodore placed the joyports right
next to the power switch, where static on your fingers can literally fry
the chip directly.  I recommend leaving joysticks plugged into both
ports at all times, to avoid this problem.  If you're lucky, all you'll
lose is joystick functionality.  The 6526's control almost every
function on your computer, so if you zap one completely, your computer
won't work at all.

Open up your computer, if you want, and find the two chips labelled with
a "6526" number somewhere on them.  If these two chips are soldered down
(ie, you can't remove them), then you're sunk - take it to a repair
shop.  If they are socketed, you can try mail-ordering a chip and
sticking it in yourself.  If you've done all that, you are a qualified
Commodore service person.  :)

-- 
David DeSimone, aka "Fuzzy Fox" on some networks.          /!/!
INET:    an207@cleveland.freenet.edu                      /  ..
Q-Link:  Fuzzy Fox                                        /   --*
Quote:   "Foxes are people too!  And vice versa."         /  ---