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Subject: Re: Joystick stuff - circuits

From: "Paul Schreiber" <synth1@...>
Date: 2000-02-22

> Would it make more sense to use the old Apple II joysticks with the DB-9
> connector? I know that these joysticks were wired directly to the pots,
the
> PC joysticks I have had, all have some type of internal processing and
send
> data instead of voltages. -Nate
>

Incorrect. The pots are brought out to individual pins. Inside the PC, dual
555 timers are
used to generate 1-shot pulses of variable width. Writing to an I/O port
(201H, I think)
resets the 1-shots, then the width is read.

Some "modern" PC chip sets use a 8-bit ADC and read the value directly.

Paul S.