Path: utzoo!attcan!uunet!zephyr.ens.tek.com!tektronix!psueea!parsely!bucket!leonard
From: leonard@bucket.UUCP (Leonard Erickson)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Tandy joystick help
Message-ID: <1904@bucket.UUCP>
Date: 10 Jan 90 07:05:07 GMT
References: <90005.184516WTW101@PSUVM.BITNET>
Organization: Rick's Home-Grown UNIX; Portland, OR.
Lines: 35

WTW101@PSUVM.BITNET (Bill Warner) writes:

>I need some help about Tandy joysticks.  I need to connect one to an
>IBM type joystick connector.  I need to know how the various signals
>from/to the Tandy joystick correspond to the IBM signals (in the DB-15
>connector.)  Does anyone out there know the pinout for the Tandy 6-pin
>DIN connector, and how or if they correspond to the IBM pinout?

Okay, here's the scoop. I can't tell from the diagram in the manual
which pot is X and which is Y. They're labeled A and B. The pots are wired
so that one side is grounded, the other side is +5v and the center tap
(slider) is the signal. They give a variable *voltage* which is fed to
a DAC. This may be a problem if the IBM expects a varying *resistance*.


DIN-6	signal
1	center tap of A pot
2	center tap of B pot
3	ground (wired to pin 3 of both pots, and to both buttons)
4	button 1 (shorts to ground when pressed)
5	+5v (wired to pin 1 of *both* pots)
6	Button 2 (shorts to ground when pressed)

If you figure out how to make the hookup without rewiring the *inside*
of the joysticks post the details. But I somehow doubt you'll do it.

In defense of Tandy, they had a reason for doing it this way. The Joysticks
for the Color Computer differ only in having 1 button and 5 pins. They wanted
to avoid the hassles involved in explaining to Joe Public that he couldn't
use his CoCo joystick on his Tandy PC. 
-- 
Leonard Erickson		...!tektronix!reed!percival!bucket!leonard
CIS: [70465,203]
"I'm all in favor of keeping dangerous weapons out of the hands of fools.
Let's start with typewriters." -- Solomon Short