Path: utzoo!attcan!utgpu!watmath!att!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!usc!cs.utexas.edu!uunet!van-bc!rsoft!mindlink!a344
From: a344@mindlink.UUCP (Tom Klok)
Newsgroups: comp.sys.atari.8bit
Subject: HD caching with Sparta
Message-ID: <519@mindlink.UUCP>
Date: 20 Sep 89 20:22:07 GMT
Organization: MIND LINK! - British Columbia, Canada
Lines: 29

A friend of mine is running BBS Express! Pro (node 86) on a 130XE running
SpartaDOS 3.2 with a 256K MIO and a 5 Meg HD (soon to be 20 Megs).  I've
noticed that SpartaDOS seems to make a lot of seeks to the HD, especially when
writing files.  Since Pro likes to keep everything well split up in lots of
subdirectories, it's my guess that Sparta is following the directory chain
around the disk every time a file is opened, especially if the filename
specifies a path from the route (ie "D3:>PRO>DATA>FILE.DAT").  The net effect
is that it can take upwards of 2 seconds to open a file, even though burst
access is very fast once the file is open.

So, my question to all you Atarians is this:  does anybody have a program to
use the extended 64k of the XE to supply caching for the hard drive?  I figure
if the bitmap, directory and sector link sectors were kept in ram, and Sparta's
read calls were intercepted so the sectors were supplied from ram instead of
going to the disk, the speed could be increased by a huge amount, perhaps
almost as fast as a ramdisk.  Write operations would be done through the cash
to the disk immediately; I think delayed writes is asking too much of the
existing software.

If someone has a cache, or knows of someone that does, I'd really like to take
a look at it.  If not, I might attempt to write one in MAC/65, but I'd need
better docs on the internals of Sparta and the MIO than I now have.  This, too,
would be much appreciated.

Thanks to all that reply.

Tom Klok    aka ZedOne   cosysop of Sin City BBS 604-321-9925
a344@mindlink.uucp or tom_klok@mindlink.uucp
voice # 604-321-1809