Computer File Systems

Factual Questions
1

You know, like FAT, FAT32 and NTFS.

  1. How many of these are there? Is there some sort of comprehensive list somewhere?

  2. What is their structure? How do they work? (In a general sense; I assume each one is different.)

2

NTFS5 vs. FAT32

look under the “reference” section

good short overview of file systems

comparison

Inside NTFS

3

There are quite a few of them. Just to get a feel for how many, look at Filesystems HOWTO. They list (among others):
FAT 12/16/32, VFAT, HPFS, NTFS, Ext, Ext2, Ext3, HFS, ADFS, AFFS, BeFS, BFS, DTFS, EFS, FFS, GPFS, HFS, HTFS, JFS, LFS, MFS, NWFS, FSS, ODS, QNX, ReiserFS, SES, V7 XFS and XiaFS.
But there are others.
astros link is a good starting point. I have been looking around for a good intro to FAT12 (used on floppies), but with dismal results.

4

link to bootstrap tutorial with fat12 file structure below

The FAT12 file system is commonly used on floppy disks. The source code example below demonstrates how to read the root directory to search for the file, how to traverse the FAT to load the file into memory, and how to begin executing the loaded code