Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!samsung!munnari.oz.au!comp.vuw.ac.nz!actrix!David.Empson
From: David.Empson@actrix.gen.nz (David Empson)
Newsgroups: comp.sys.apple2
Subject: Re: ADB connects (was Re: remember DVORAK layout?)
Message-ID: <1991Jun28.141019.23186@actrix.gen.nz>
Date: 28 Jun 91 14:10:19 GMT
References: <4778.apple.a2.net@pro-nbs> <1991Jun27.015258.29179@vuse.vanderbilt.edu>
Organization: Actrix Information Exchange, Wellington, New Zealand
Lines: 20
Comment-To: benson@vuse.vanderbilt.edu

In article <1991Jun27.015258.29179@vuse.vanderbilt.edu> benson@vuse.vanderbilt.edu (Paul Benson) writes:
>   ...  In my last post I was unsure
>   about the ADB y-connector, but since the devices are not screening each
>   other for collisions and it is basically just straight wire connections
>   then it should work fine.

ADB is an open-collector bus.  You can probably have any cable
configuration you like, provided there are no loops in it and the
maximum length isn't exceeded.  There is no problem with Y junctions.

The main limits (from the IIgs Hardware Reference):

Maximum cable length 5 metres, maximum power drain 500 mA (5V).  Cable
capacitance should not exceed 100 pF per metre.

By the way: ADB devices are connected in PARALLEL.  The apparent
serial connections are an illusion.
-- 

David.Empson@bbs.actrix.gen.nz