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From: allisonp@world.std.com (Allison J Parent)
Message-Id: <199802010420.AA07172@world.std.com>
To: pups@minnie.cs.adfa.oz.au
Subject: Re: Installing PDP-11 UNIX w. no tape - solution
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<> they can only because the '450 has a silo of 4 bytes 
<
<The 16540 has only one byte buffer.

Oops mixed it op with a compatable hybrid...

<
<> and the 550 it's either 16 or 32 bytes.
<
<The 16550 has 4 bytes, and the 16650 has (I think) 16 bytes.

Some fo the super integration chips (FDC, IDE, 2SIO and parallel) have 
extended that to 32.


<Have you modified the kernel?  Normally disks will preempt ttys.

This is RT-11 and RSTS and I don't have a UNIX on the q-buss -11s.
I could recompile RT but, Qbus, interrupt priority is based on position 
relative to the cpu, In mine its memory, serial io and then all the rest 
in order of decreasing speed.


Allison