From owner-freebsd-hackers Tue Oct 10 19:51:44 1995 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.6.12/8.6.6) id TAA19005 for hackers-outgoing; Tue, 10 Oct 1995 19:51:44 -0700 Received: from genesis.atrad.adelaide.edu.au (genesis.atrad.adelaide.edu.au [129.127.96.120]) by freefall.freebsd.org (8.6.12/8.6.6) with ESMTP id TAA18997 for ; Tue, 10 Oct 1995 19:51:40 -0700 Received: from msmith@localhost by genesis.atrad.adelaide.edu.au (8.6.9/8.6.9) id MAA13239; Wed, 11 Oct 1995 12:50:16 +0930 From: Michael Smith Message-Id: <199510110320.MAA13239@genesis.atrad.adelaide.edu.au> Subject: Re: non-sio UART driver To: terry@lambert.org (Terry Lambert) Date: Wed, 11 Oct 1995 12:50:16 +0930 (CST) Cc: bde@zeta.org.au, hackers@FreeBSD.ORG, msmith@atrad.adelaide.edu.au In-Reply-To: <199510101825.LAA10775@phaeton.artisoft.com> from "Terry Lambert" at Oct 10, 95 11:25:03 am Content-Type: text Content-Length: 1160 Sender: owner-hackers@FreeBSD.ORG Precedence: bulk Terry Lambert stands accused of saying: > > What's a multidrop serial bus? > > You know; like an Altos 2000. 8-). Ah, Terry, off on an historic trip again 8) Unfortunately, nothing so romantic. '485 is used lots in industrial applications because you can run it insanely long distances in really noisy environments, and in 9-bit mode writing code for a micro to interact with it is trivially easy. > > If you need to do any normal serial i/o to a 16x50 then I suggest adding > > to sio. > > It's not; it's a muxed 422/424 connection to multiple uarts in a > fan-out box. It's actually a 232 to 2-wire 485 adapter that uses DTR to control the drive/listen input on the 485 driver. It consists of two chips (MAX232 and MAX485) and some jellybeans. > Terry Lambert -- ]] Mike Smith, Software Engineer msmith@atrad.adelaide.edu.au [[ ]] Genesis Software genesis@atrad.adelaide.edu.au [[ ]] High-speed data acquisition and [[ ]] realtime instrument control (ph/fax) +61-8-267-3039 [[ ]] My car has "demand start" -Terry Lambert UNIX: live FreeBSD or die! [[