Path: utzoo!attcan!uunet!mailrus!usenet.ins.cwru.edu!eagle!data!mustang!nntp-server.caltech.edu!fjs
From: fjs@nntp-server.caltech.edu (Fernando J. Selman)
Newsgroups: comp.sys.next
Subject: Re: RS-423 on new machines -- What is it?
Message-ID: <1990Sep26.122134.4256@nntp-server.caltech.edu>
Date: 26 Sep 90 12:21:34 GMT
References: <688@happym.UUCP>
Distribution: na
Organization: California Institute of Technology, Pasadena
Lines: 30

irv@happym.UUCP (Irving [h] Wolfe) writes:

>What's RS-423?  I've used RS-232 for nearby serial devices and RS-422 for
>terminals 700 feet from the computer, but what is this RS-423 that the new
>NeXT machines have, and what can it be interfaced to?
>-- 
> [stuff deleted]

From the latest Horowitz and Hill, page 727:


		       RS-232		RS-423A		RS-422A
	               ======		=======		=======

Mode	            single-ended	single-ended	differential

Maximun Number
	Drivers          1                    1             1
	Receivers        1	             10            10

Maximun Cable Length	15m                1200m         1200m

Maximun Data Rate(bit/s) 20k                100k           10M

Transmit Levels	      +-5V min		+-3.6V min	+-2V min
		      +-15V max		+-6.0V max	(diff'l)

etc.

			Fernando