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From: tom@bumrl1.bu.edu (Tomislav Lozic)
Newsgroups: sci.electronics
Subject: Re: Converting RS-422 to RS-232
Message-ID: <70419@bu.edu.bu.edu>
Date: 11 Dec 90 01:48:09 GMT
References: <1990Dec10.173757.1162@ccu.umanitoba.ca>
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Reply-To: tom@bumrl1.bu.edu (Tomislav Lozic)
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In article <1990Dec10.173757.1162@ccu.umanitoba.ca>, kujanpa@ccu.umanitoba.ca writes:
|> 
|> Can I build a circuit to change from RS-422 to RS-232?
|> Can this circuit be powered from the Mac SE port?
|> Using an external power supply is ok, but if the    
|> circuit could be powered from the line it would be
|> great.
|> 

You _can_ build such a circuit. However, if you have better
things to do, you can buy RS-232 to RS-422 converter for
about $10-$15 from B&B electronics. 

Their address is:
	B&B electronics
	P.O.Box 1040
	Ottawa, Illinois 61350

The part is:	RS-232 to RS-422 converter (model 422CFC)

It comes together with a required power-supply (12V, 100mA).
[ I don't know of any such circuit that is powered from SI port ]

NOTE:	To have a good long-distance performance connect the converter
	at RS-232 side and use RS-422 cable. (More expensive but
	also more reliable than long RS-232 cable.)

___________________________________
Tomislav Lozic  <tom@bumrl1.bu.edu>