AMSDOS file headers

[zhulien]

Hi

Is this page correct?

https://www.cpcwiki.eu/index.php/AMSDOS_Header

Why would a filename be in an actual file header? 

[HAL6128]

It is correct (see Firmware:  s968se09.PDF (cpcwiki.eu)).

I couldn't answer the "why".  (developer intention?)

[pelrun]

It doesn't matter for a disk file, but note the fields that are tape only - this is also the TAPE file header (https://www.cpcwiki.eu/imgs/5/5d/S968se08.pdf), and that absolutely needs the filename in it.

[zhulien]

ah thanks, at least CPC has the same header layout for both tape and disc - I was reading about the MSX headers and was confused a bit why they would make 2 different headers (for tape and disc) - actually they have more than 2 for disc even.

I guess cos tape doesn't have the concept of an allocation table or directory.

[HAL6128]

Actually the tape header can have a 16 characters name whereas disc has 8.3.

[GUNHED]

The Amsdos file header was expanded (in a 100% compatible way) for FutureOS. Now it contains an icon or short file description. Also 24 bit for file length, supporting files up to 16 MB. And data for loading the file into expansion RAM etc (see FutureOS manual).

[pelrun]

Actually the tape header can have a 16 characters name whereas disc has 8.3.

Sure, however even in the disc header there is still *room* for a 16 character name, and it doesn't matter because it's the directory that holds the actual filename.

[HAL6128]

Yes, you are right; @zhulien asked regarding the header layout (tape/disc) and they are different.