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 is the first DOS to support the Vortex format which become a standard format later on.

RSX Commands in German and English; VDOS differences compared to AMSDOS

Some commands are available in German and English language. This is an advantage when using more than one DOS ROM at the same time.
Vortex is a German company, so they added RSX commands in German and English language. The normal AMSDOS RSX commands |TAPE.xx and |DRIVE/|USER were added as |CAS and |SELECT (which resemble equivalent German words Kassette and Selektieren). Also Dobbertin's X-DDOS does supports both the English and German languages).

|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.