Path: utzoo!utgpu!watmath!watdragon!rose!ccplumb
From: ccplumb@rose.waterloo.edu (Colin Plumb)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Sick, sick idea...
Message-ID: <17356@watdragon.waterloo.edu>
Date: 18 Oct 89 21:17:14 GMT
References: <17243@watdragon.waterloo.edu> <1989Oct16.143322.29737@sjsumcs.sjsu.edu>
Sender: daemon@watdragon.waterloo.edu
Reply-To: ccplumb@rose.waterloo.edu (Colin Plumb)
Organization: U. of Waterloo, Ontario
Lines: 18

In article <1989Oct16.143322.29737@sjsumcs.sjsu.edu> 33014-18@sjsumcs.SJSU.EDU (Eduardo Horvath) writes:
>In article <17243@watdragon.waterloo.edu> ccplumb@rose.waterloo.edu (Colin Plumb) writes:
>> The normal way to send a break, as far as I know, is to drop the baud rate
>> really low and send a null byte (up to 15 null bits, actually).
>
>	While I have not been working with the Amiga serial port hardware,
> I have recently been working with an embedded system that has a MC68681
> ( I think I have the right part number ) which is a DUART chip.  To send
> a break with that, you set the break time, and give a special command.
> The DUART does all the rest.

I should have been clearer... the normal way to send a break *with the Amiga
serial hardware* is to play tricks with the baud rate.  Other chips have
different techniques.  The Z8530 has a control register bit that forces
a space condition on the line until the bit is cleared.  There are other
approaches.
-- 
	-Colin