User:Superleaf1995/AFPFS: Difference between revisions

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There are no FATs or whatsoever.
There are no FATs or whatsoever.

== File entry ==


After the SOF there is file metadata Wich is:
After the SOF there is file metadata Wich is:

1-byte wide of filename
1-byte wide of filename
filename wide as (above byte + 1)
filename wide as (above byte + 1)

3-bytes wide extension
3-bytes wide extension

2-byte indicating group
2-byte indicating group

2-byte indicating member ID in group (same IDs in multiple files means that they are the same file but split up)
2-byte indicating member ID in group (same IDs in multiple files means that they are the same file but split up)



Revision as of 22:47, 15 December 2019

AFPFS abritary file positioning file system is a theoric and proven (in my own personal DOS-alike OS)


Bootsector

The bootsector has information like bytes per sectors, heads, and label. Then the boot thingy.


Files

The FS views the disk as a array, a big one.

There are no directories, there are only 'groups' in files. Every file arbitraryly uses 0FF8h as SOF (Start of file), when 0FF8h, means that there is a new file. 0FF9h means that this is the last file in partition and works as an EOF for the entire partition, leaving the empty part untouched until written on, and allowing for multiple partitions.

There are no FATs or whatsoever.

File entry

After the SOF there is file metadata Wich is:

1-byte wide of filename filename wide as (above byte + 1)

3-bytes wide extension

2-byte indicating group

2-byte indicating member ID in group (same IDs in multiple files means that they are the same file but split up)

And then the file data.

The good of this filesystem is that since there is no file table, the files will always be indexed in disk. Regardless of a corrupt file or sector.

This Filesystem can be simpler than FAT if we remove the groups and tune it a bit.

Still, leave the floppy signature at the end of the boot sector.

Note: Only tested on floppy disk, requires bytecopiers to copy to a floppy image. And have to manually put the file metadata on all files. (ASM simplifies this).