Path: utzoo!attcan!uunet!husc6!mailrus!ncar!noao!asuvax!fbog!dbk
From: dbk@fbog.UUCP (Dave B. Kinzer @ Price Rd. GEG)
Newsgroups: comp.sys.amiga.tech
Subject: Analog Joysticks
Summary: I'm a gonna do it!
Keywords: Analog, Joystick, Full-range
Message-ID: <1384@fbog.UUCP>
Date: 5 Nov 88 22:11:41 GMT
Reply-To: dbk@fbog.UUCP (Dave B. Kinzer @ Price Rd. GEG)
Followup-To: comp.sys.amiga.tech
Distribution: na
Organization: Motorola Microcomputer Division, Tempe, Az.
Lines: 43

[I just don't get those lineeater jokes.             heh heh heh]

  OK, here is the summary so far.   As a response to a challenge issued
right here on the net, I decided to write an article to advance the
state of the Amiga.  I chose a topic, an analog joystick.  I then designed
a circuit to adapt IBM and Apple joysticks to work with the Amiga (I
understood how the hardware works, so this part wasn't hard), writing the
article as I went along.  
   I then got to the point of writing a sample program, to demonstrate
the software interface.  What software interface you say?  Imagine my
surprise!  I had ASSUMED it existed.  Well, I resolved to fix this
shortcoming and do so in a proper manner.
   I am writing a *device-driver* to take care of analog joysticks.  It
will be a logical extension of the present gameport device so little
revamping of the application programs will be necessary if C-A picks it up.
(Hopefully only the device name will have to change.)
   My current plan is to make the device driver freely available (I owe the
public domain that much), publish an article on how to make the joystick
adapter (for those who like these kinds of things), make a pc-board 
available for those who don't want to hack their own, and *sell* an
adapter for those who do not want to mess with it at all.  Also in the
article will be the example program with text as to how to call the driver,
using center deadbands and dead end zones.
   The driver and sales ideas have come late in this development, but seem
necessary to assure software vendors will pick up on the idea.  
   I am sure I will need some help doing this driver, many many holes
exist in the RKM documentation of this.


   Some people on the net have been proposing that a capacitor paralleling
the internal Amiga joyport capacitors will fix the joysticks.  This is
essentially true and a very low cost way of adapting the controller, but
unless you know what is going on inside the Janus chip (I know I don't have
the max power specs), it seems a little dangerous (as explained in the
article).  Of course, since apparently you can connect +5 directly to the
pin (joystick in zero ohm position), it should work.



-- 
|     // You've heard of CATS and DOGS, I'm from GOATS, Dave Kinzer         |
|    //  Gladly Offering All Their Support!             noao!nud!fbog!dbk   |
|  \X/   "My employer's machine, my opinion."           (602) 897-3085      |