VDOS

The disc operating system VDOS was developed by the German company Vortex.

It was provided for use with the Vortex Disc Drives from Vortex (F1-D, F1-S, F1-X, M1-D, M1-S or M1-X).

VDOS was supplied on an EPROM, and was released in 3 versions:

VDOS 1.0
VDOS 2.0
VDOS 2.11

Further there were German and English versions of this ROMs.

The VDOS ROM also contained a machine language monitor.

VDOS primarily supported the Vortex format which become a standard format later on.

Germanized-English RSX Commands and VDOS differences compared to AMSDOS

Vortex apparently considered the normal AMSDOS RSX commands |TAPE.xx and |DRIVE/|USER too difficult for german users, and changed them to |CAS and |SELECT (which resemble equivalent german words Kassette and Selektieren). This is making VDOS slightly incompatible with AMSDOS and all other AMSDOS clones (except for Dobbertin's X-DDOS, which supports both the english and germanized dialects).

|SELECT is used to both select user and/or drive. e.g. |SELECT,"3" for user 3, |SELECT,"B" for drive B, |SELECT "4B" for user 4 on drive B. VDOS doesn't have USER or DRIVE commands.

When using CAS CATALOG you give the address of a buffer to fill with the list of files in the current user and drive. The format of this data differs compared to AMSDOS.

AMSDOS uses:

<ff> <8 bytes filename> <3 bytes extension> <2 bytes size in K> with a byte of 00 to indicate the end of the list.

VDOS uses:

<user> <8 bytes filename> <3 bytes extension> <2 bytes size in K> with a byte of FF to indicate the end of the list.

This is important if you use CAS CATALOG and parse the data to fetch the list of files.