Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!cornell!rbrown
From: rbrown@svax.cs.cornell.edu (Russell Brown)
Newsgroups: comp.sys.atari.8bit
Subject: Re: Serial Interface
Message-ID: <22722@cornell.UUCP>
Date: 18 Nov 88 14:59:02 GMT
References: <9657.192.forumexp@mts.rpi.edu>
Sender: nobody@cornell.UUCP
Reply-To: rbrown@svax.cs.cornell.edu (Russell Brown)
Organization: Cornell Univ. CS Dept, Ithaca NY
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In article <9657.192.forumexp@mts.rpi.edu> george burdell writes:
>
>  a little box that plugged into a joystick port to turn it into a serial port.
>  I don't think building one would be a problem ... components can be had.

This can be done with a single chip.  There is a nifty little chip called the
MAX232CPE which allows you to convert RS232 voltage levels to TTL levels with no
extra power supply (i. e. with just the five volts available on the joyport).
This can be hooked up to two of the PIA pins in the joyport, as well as the
voltage lines.  Only problem with this approach is that it may require a
prohibitive amount of onboard software - I don't know how much the device
handler which would have to be written would entail, or how much of the work
which has to be done can be abstracted to the handler.  It may be that you would
also need to add shift-registers and an external clock, but these are all still
non-proprietary chips.

Russell G. Brown