Disk image layout - is there a doc?

[leibnitz27]

Hi All -

So I'm messing around with getting back into CPCs, and one thing I'd like to do is understand the layout of a CPC disk image, by just writing something in C to look at files on a DSK (but without doing a full blown emulator!!  )

The file format for the DSK image shows me how the physical data is laid out, Format:DSK disk image file format - CPCWiki , which is great, but are there any docs as to how a DATA formatted disk is laid out given this? 

When I've been digging, I keep on ending up at "get the catalog by calling CAS CATALOG (BC9B)" Unofficial Amstrad WWW Resource - what I'd like is - has anyone documented the equivalent of the FAT, so I can do this by hand without firmware present?   (I'd look at eg the source for CPCloader, but it doesn't seem to be open source   , unless I've missed something really obvious!   )

Cheers!

[arnoldemu]

Hi All -

So I'm messing around with getting back into CPCs, and one thing I'd like to do is understand the layout of a CPC disk image, by just writing something in C to look at files on a DSK (but without doing a full blown emulator!!  )

The file format for the DSK image shows me how the physical data is laid out, Format:DSK disk image file format - CPCWiki , which is great, but are there any docs as to how a DATA formatted disk is laid out given this? 

When I've been digging, I keep on ending up at "get the catalog by calling CAS CATALOG (BC9B)" Unofficial Amstrad WWW Resource - what I'd like is - has anyone documented the equivalent of the FAT, so I can do this by hand without firmware present?   (I'd look at eg the source for CPCloader, but it doesn't seem to be open source   , unless I've missed something really obvious!   )

Cheers!

DATA, SYSTEM and IBM are all variants of the CP/M filesystem.

DATA has no system tracks, SYSTEM has 2 system tracks.
The directory blocks follow.

This is a good reference:
CP/M information archive : disc formats
CP/M information archive : disc formats

[leibnitz27]

Great, thanks!

[arnoldemu]

Great, thanks!

you're welcome