From owner-freebsd-hackers Sun Oct 22 19:44:04 1995 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.6.12/8.6.6) id TAA17622 for hackers-outgoing; Sun, 22 Oct 1995 19:44:04 -0700 Received: from etinc.com (etinc-gw.new-york.net [165.254.13.209]) by freefall.freebsd.org (8.6.12/8.6.6) with ESMTP id TAA17617 for ; Sun, 22 Oct 1995 19:43:59 -0700 Received: from trumpet.etnet.com (trumpet.etnet.com [129.45.17.35]) by etinc.com (8.6.11/8.6.9) with SMTP id XAA08508; Sun, 22 Oct 1995 23:00:57 -0400 Date: Sun, 22 Oct 1995 23:00:57 -0400 Message-Id: <199510230300.XAA08508@etinc.com> X-Sender: dennis@etinc.com X-Mailer: Windows Eudora Version 2.0.3 Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" To: Kim Culhan From: dennis@etinc.com (dennis) Subject: Re: Bragging rights.. Cc: hackers@freebsd.org Sender: owner-hackers@freebsd.org Precedence: bulk > >I've been using a pair of Adtran ISU128's for some time, they do both >sync and async; I'm not tellin' which I'm using :) > >I do have one complaint though. The async interfaces have TTL voltage >levels though they supply these little 'adapters' labeled to >suggest they convert the RS530 async. connections to RS232. > They can't exactly do this, because EIA-530 is synchronous RS-422 (balanced) and RS-232 is unbalanced, so they have to do signal conversion. They probably default to RS-232 for async and run EIA-530 for sync. I doubt if RS-232 would work at RS-422 levels at higher speeds as RS-232 is only spec'ed for 20k anyway. Dennis ---------------------------------------------------------------------------- Emerging Technologies, Inc. http://www.etinc.com Synchronous Communications Cards and Routers For Discriminating Tastes. 56k to T1 and beyond. Frame Relay, PPP, HDLC, and X.25