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From: dave@horsfall.org (Dave Horsfall)
Subject: [TUHS] Calgary buffer modifications
Date: Wed, 31 Jan 2018 10:42:42 +1100 (EST)	[thread overview]
Message-ID: <alpine.BSF.2.21.1801311037520.7787@aneurin.horsfall.org> (raw)
In-Reply-To: <D2E297C4-EB1D-4A5F-876B-160AF8F3ABB7@planet.nl>

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On Tue, 30 Jan 2018, Paul Ruizendaal wrote:

> “One widely distributed (though undocumented) solution to this hardware 
> limit on the model 40 was a version of Unix by Robert Sidebotham, 
> Faculty of Environmental Design, University of Calgary. His solution was 
> to move the I/O buffers out of kernel space.”

I wonder if that inspired the AUSAM buffer management?  The current buffer 
header was "b" (like "u") which got mapped by KISA5.

For the first time I was able to avoid our 11/40 deadlocking; I can't 
remember all the devices that were on it, but there were a *lot* 
(including the printer driver etc which used the buffer pool, not the 
character queue).

-- 
Dave Horsfall DTM (VK2KFU)  "Those who don't understand security will suffer."


      parent reply	other threads:[~2018-01-30 23:42 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-30 10:28 Paul Ruizendaal
2018-01-30 14:18 ` Clem Cole
2018-01-30 23:42 ` Dave Horsfall [this message]

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