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From: Ordania-DM@cup.portal.com (Charles K Hughes)
Newsgroups: comp.sys.atari.8bit
Subject: Re: Upgrades
Message-ID: <29635@cup.portal.com>
Date: 5 May 90 20:20:08 GMT
References: <9005040713.AA13536@ucbvax.Berkeley.EDU>
Organization: The Portal System (TM)
Lines: 23

Scott writes:
-------------
>Charles Hughes, I was hoping that I could build a modem that was
>completely variable. I got the idea from Antic magazine which featured
>the parallel bus. I only have the 3rd instalment of the article. Its in
>the March 1985 issue. In it they have a schematic of a setup that uses
>the parallel port and it has a baud rate generator in it. What I was
>wondering is there a way to convert what they have down, I beleive its
>for a serual I/O board, to a modem that can go to the same baud rates
>that they have down for it....50 to 19200 bd. Is this possible?

  IMHO no.  I have the issues and I do know what you are talking about, but
you are getting confused between what a serial I/O board does and what a modem
does.  A modem converts a serial stream of data into tones that can be 
transmitted via telephone.  A serial I/O board merely converts bytes into 
on/off transitions of a serial line - to a telephone this would be roughly 
equivalent to lifting the phone up and putting it back down rapidly.  You 
can use the serial I/O board as an RS232 interface and then add a nice modem.

>
>     UCI144@URIACC.Bitnet                       Scott Glynn

Charles_Hughes@cup.portal.com