[comp.sys.atari.st] CACHEXXX,

apratt@atari.UUCP (Allan Pratt) (10/21/89)

Ritzert@DMZRZU71.BITNET writes:

>According to Allan, XXX must be exactly equal to the size of the FAT.

Please, this is a gross misunderstanding.  If it *had* to be exactly
equal to anything, we would have written it to compute that thing
when it ran.

What I said is that there's little point in making XXX GREATER than
the sum of the FAT sizes.

>Related question: is it possible with tos14 to increase the cluster
>size, i.e. shorten the FATs dramatically and thus speed up the hd even
>further? Will CACHEXXX support such a configuration?

TOS 1.4 FAT handling is so fast, you wouldn't notice.  My God, it's
DOZENS of times faster than TOS 1.2 FAT handling, and certainly
acceptably fast in its own right!  When the FAT is entirely cached, a
Dfree() call on a 16MB partition takes under a second!  That's  fast
enough for me.

HDX on release 3.01 of the Atari Hard Disk Utilities disk allows you to
create partitions greater than 16MB in size.  It accomplishes this by
making "sectors" on the disk appear to be larger than 512 bytes. A
cluster is always two sectors, but larger sectors means more data per
cluster, and therefore fewer FAT entries.  Not all disk utilities use
Getbpb() to find out how big a sector is, so they won't all work with
this kind of partition. For maximum compatibility, therefore, this
feature only kicks in on large (>16MB) partitions.

CACHEXXX *does* support the larger sector size.  No other cache program
can, because it doesn't know where to look to find the sector size it
should use.  Don't use any other cache program if you have any
partition >16MB created by this HDX.

FYI: on the disk labelled 3.01 you will find HDX's version number is
3.00 and AHDI's version number is 3.01.  If you use HINSTALL to make
your hard disk bootable, the version number you will see when it boots
is 3.01.  This is all well and good.  If your hard disk driver, whether
installed by HINSTALL or loaded from your AUTO folder as AHDI.PRG, says
it's version 3.00, GET THE UPDATE.  AHDI and bootable disks version
3.00 are DEADLY to data.

============================================
Opinions expressed above do not necessarily	-- Allan Pratt, Atari Corp.
reflect those of Atari Corp. or anyone else.	  ...ames!atari!apratt