From: ph@gmd.de (Peter Hendricks)
Subject: Re: Wanted: A to D hardware for a PC
To: ebuddington@eagle.wesleyan.edu
Nntp-Posting-Host: gmdzi
Organization: GMD, Sankt Augustin, Germany
Lines: 23

In <3889@ncr-mpd.FtCollinsCO.NCR.COM> Brad Wright writes:

>	If you know much about PC's (IBM comp) you might try the joystick
>port.  Though I haven't tried this myself, I've been told that the port
>has built in A-D converters.  This would allow the joystick to be a couple of 
>pots.  If you could find the specs this might just work for you...

I guess 100k, connecting pins 1-3 (1x), 1-6 (1y), 9-11 (2x), and 9-13 (2y).

Or: Get an 8-bit DA-Converter (merely a couple of transistors and
Resistors) and an OpAmp to compare its output to the voltage you want to
measure, connect them to a spared printer port (if you have one), and do
the rest by software (stepwise refinement). The port addresses for your
printer ports are probably: &H378 (LPT1), &H278 (LPT2). This should work
well enough for your purposes.

Hope this helps

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