28 Jul
2003
28 Jul
'03
5:21 a.m.
From: spc(a)conman.org
It was thus said that the Great Bob Shannon once stated:
>
---snip---
It also depends upon the size of the disk you are going to use---up to a
few meg in size the MS-DOS FAT system (12 or 16 bit variants) will probably
be the best bet---well documented with the ability for interoperability
between most systems.
-spc (my two bits worth ... )
Hi Bob
If you absolutely must start with a FAT system I think that
you should use a DOS like FAT. This makes things easy to
move from machine to machine. The 12 bit FAT is a little clumsy
so I'd suggest the 16 bit as the easier to deal with.
Dwight
28 Jul
28 Jul
5:52 a.m.
On Mon, 28 Jul 2003, Dwight K. Elvey wrote:
If you absolutely must start with a FAT system I
think that
you should use a DOS like FAT. This makes things easy to
move from machine to machine. The 12 bit FAT is a little clumsy
so I'd suggest the 16 bit as the easier to deal with.
FAT16 is limited to 4G
But DOS and Win9x limits it to 2147483647 (NTx permits 4G).
The 2G limitation is due to the use of signed long ints in places that
should have an UNSIGNED long int. Because of that, it can have files with
a NEGATIVE size!
One of my hard drives was getting crowded; I was down to less than a meg
of free space. So, I stepped on the directory of a floppy, and created
a file that reported a size of -2147483648. Surely, if I copied a file
with that much negative size to the drive, it would give me more free
space! But it was unable to do the COPY.
6:08 a.m.
Fred Cisin wrote:
On Mon, 28 Jul 2003, Dwight K. Elvey wrote:
Now is a good time to back up your system. AND MAKE SURE THE BACK UP WORKS!
If you absolutely must start with a FAT system I
think that
you should use a DOS like FAT. This makes things easy to
move from machine to machine. The 12 bit FAT is a little clumsy
so I'd suggest the 16 bit as the easier to deal with.
FAT16 is limited to 4G
But DOS and Win9x limits it to 2147483647 (NTx permits 4G).
The 2G limitation is due to the use of signed long ints in places that
should have an UNSIGNED long int. Because of that, it can have files with
a NEGATIVE size! 
6:13 a.m.
Fred Cisin wrote:
One of my hard drives was getting crowded; I was down
to less than a meg
of free space. So, I stepped on the directory of a floppy, and created
a file that reported a size of -2147483648. Surely, if I copied a file
with that much negative size to the drive, it would give me more free
space! But it was unable to do the COPY.
You should've used PKZIP. If your negative length file contained only
nulls, they would compress very well, maybe down to -100 bytes or so. If
you add on the zip header information, you'd end up with a zip file with
a very small positive length (call it 200 bytes). You copy this 200-byte
file to your hard disk and unzip it to recreate the original -2GB file.
I think there are only two problems with this:
1. You won't gain anything if you're running with compression on your
hard disk.
2. My glass is empty.
- Paul
6:15 a.m.
FAT16 is limited to 4G
But DOS and Win9x limits it to 2147483647 (NTx permits 4G).
The 2G limitation is due to the use of signed long ints in places that
should have an UNSIGNED long int. Because of that, it can have files with
a NEGATIVE size!
Fred, I think another reason for this limit is that DOS only allows the
allocation unit (cluster) size be an even power of two. That leaves out a
lot of possible values. If Bob is willing to "forgive" DOS compatibility,
he could allow any allocation unit size that fits in a byte (so 255
theoretically, but he could also choose a 16- or 32-bit factor), allowing
for a much higher limit. --Patrick
6:11 a.m.
Hi Bob
If you absolutely must start with a FAT system I think that
you should use a DOS like FAT. This makes things easy to
move from machine to machine. The 12 bit FAT is a little clumsy
so I'd suggest the 16 bit as the easier to deal with.
Dwight
I'll second that! Although it's just a little shifting, I'm a lazy
programmer type and debugging allocation problems in your implementation
will be easier when everything is aligned on byte/word boundaries. :-)
Patrick
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5 comments
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participants (5)
-
bfranchuk＠jetnet.ab.ca -
cisin＠xenosoft.com -
dwightk.elvey＠amd.com -
patrick＠evocative.com -
paul＠frixxon.co.uk