Digest Number 527
Archiver
Posts: 46,084
Thanks.
The data I needed really is in the FAT document after all, but it's just one
little paragraph. I had to use WinHex to see it for myself. It's not a
complicated as I thought.
Basically, the directory entry points to the first cluster. To get the
rest, you have to refer to the FAT table. Starting at the first cluster's
offset (where you'll find FFFF), just keep going through a list of cluster
references till either the next FFFF or until you've accessed the entire
file. (The file length, in bytes, is found in the directory listing) I
haven't figured out which to go by. I think the file size would be more
reliable since files don't fill their last cluster.
My application is stand-alone data acquisition to a CSV or TXT file that can
be directly accessed from a dos/windows machine.
Barry
Message: 5
Date: Fri, 9 Mar 2001 08:49:54 -0500
From: "D. Daniel McGlothin" <ddm@r...>
Subject: RE: Re: Interface to Compact Flash or PCMCIA?
You might try the book _FreeDOS Kernal_, by Pat Villani, (c) 1996 R & D
Books. It describes itself as an "MS-DOS Emulator for Platform Independence
& Embedded Systems Development". It does go into some detail of the FAT
File System. The book takes you from a formatted floppy to a platform
independent, fairly complete clone of MS-DOS v3.1, written in C and some
assembly.
It also has references the FreeDOS Project:
http://sunsite.unc.edu/pub/micro/pc-stuff/freedos/freedos.html which
resolves to an ftp site.
Take a look if you are rolling your own file system.
Regards,
Daniel McGlothin
The data I needed really is in the FAT document after all, but it's just one
little paragraph. I had to use WinHex to see it for myself. It's not a
complicated as I thought.
Basically, the directory entry points to the first cluster. To get the
rest, you have to refer to the FAT table. Starting at the first cluster's
offset (where you'll find FFFF), just keep going through a list of cluster
references till either the next FFFF or until you've accessed the entire
file. (The file length, in bytes, is found in the directory listing) I
haven't figured out which to go by. I think the file size would be more
reliable since files don't fill their last cluster.
My application is stand-alone data acquisition to a CSV or TXT file that can
be directly accessed from a dos/windows machine.
Barry
Message: 5
Date: Fri, 9 Mar 2001 08:49:54 -0500
From: "D. Daniel McGlothin" <ddm@r...>
Subject: RE: Re: Interface to Compact Flash or PCMCIA?
You might try the book _FreeDOS Kernal_, by Pat Villani, (c) 1996 R & D
Books. It describes itself as an "MS-DOS Emulator for Platform Independence
& Embedded Systems Development". It does go into some detail of the FAT
File System. The book takes you from a formatted floppy to a platform
independent, fairly complete clone of MS-DOS v3.1, written in C and some
assembly.
It also has references the FreeDOS Project:
http://sunsite.unc.edu/pub/micro/pc-stuff/freedos/freedos.html which
resolves to an ftp site.
Take a look if you are rolling your own file system.
Regards,
Daniel McGlothin