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Date: Wed, 11 Oct 1995 13:05:36 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199510110305.NAA17926@godzilla.zeta.org.au>
To: bde@zeta.org.au, msmith@atrad.adelaide.edu.au
Subject: Re: non-sio UART driver
Cc: hackers@freebsd.org
Sender: owner-hackers@freebsd.org
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>This doesn't sound unreasonable, although it wasn't clear whether you could
>guarantee that you'd get a whole packet passed down to the sio driver
>at once.  Going on and off the bus inside a packet isn't viable, as you
>generate glitches that can throw the listener off.

In fact it's guaranteed that ttwrite() will split up output into buffers
of size OBUFSIZ = 100.  However, this the double buffering should hide
any glitches.  Glitches would also decrease througput so I don't want
them.

Bruce