Path: utzoo!utgpu!jarvis.csri.toronto.edu!eecg.toronto.edu!leblanc
Newsgroups: comp.sys.cbm
From: leblanc@eecg.toronto.edu (Marcel LeBlanc)
Subject: Re: disk drive comparisons
Message-ID: <1990Feb15.194236.6799@jarvis.csri.toronto.edu>
Summary: the 1581 is quite well organized
Organization: EECG, University of Toronto
References: <1990Feb15.091120.19625@ccu.umanitoba.ca> <15@tygra.UUCP>
Date: 16 Feb 90 00:42:36 GMT
Lines: 21

In article <15@tygra.UUCP> wbks@tygra.UUCP (Sean Burke) writes:
>I wonder why commodore has the 1581 set up in the strange way it does?  
>I mean, why not just use the physical disk format instead of having to run
>everything through the drive controller.  I believe that drive access would
>have been sped up considerably this way.

You should check your facts before complaining about Commodore's
organization of the 1581.  The logical vs. physical organization maintains a
better level of compatibility with the 1541 (a single sided device).  This
also hides the fact that 1581 physical sectors are 512 bytes in length

The logical to physical translation requires a trivial amount of time.  The
'drive controller' doesn't do any of this.  Removing the logical to physical
translation step wouldn't speed up the 1581 at all.  With most fast loaders
(that can handle the 1581), the load/save speed on the 1581 is 10x the speed
of a 1541.

Marcel A. LeBlanc	   | University of Toronto -- Toronto, Canada
"leblanc@eecg.toronto.edu" | and: LMS Technologies Ltd, Fredericton, NB, Canada
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