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Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!ihnp4!inuxc!pur-ee!uiucdcs!trsvax!mikey
From: mikey@trsvax.UUCP
Newsgroups: net.ham-radio
Subject: Re: RTTY interface, and Packet informati
Message-ID: <52800043@trsvax.UUCP>
Date: Fri, 4-Jan-85 17:03:00 EST
Article-I.D.: trsvax.52800043
Posted: Fri Jan  4 17:03:00 1985
Date-Received: Wed, 9-Jan-85 03:36:42 EST
References: <606@asgb.UUCP>
Lines: 22
Nf-ID: #R:asgb:-60600:trsvax:52800043:000:958
Nf-From: trsvax!mikey    Jan  4 16:03:00 1985



Why buy an interface?  You can build one for less than $50, and that
includes the box, cables, and power supply.  Using the Exar chips, a
basic RTTY interface can be built with just two additional chips, 
a 1488 and a 1489.  If you get ingenious, you can even get rid of
these.  The only other chip you might want is a driver for TX function.
This makes a total of 5 chips, plus passive parts.  Chip cost is under
$12.  If you're like me, the board will lay out exposed for a long time
till you finally box it.

The only difficult part is all the gottcha's on the RS-232.  Things like
will your RS-232 transmit without CD?  How hard is it to use DTR to
trigger your transmitter?  This kind of stuff.  If you build it in a 
box with switches, you can just hardwire a forced CD and CTS and use
a dumb terminal package to transmit and receive.

Hardware is the easy part, just tedious.  The software can be as complex
as you want it to be.

mikey at trsvax