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The disc operating system VDOS was developped 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 supported as first DOS 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.

  • AMSDOS allows you to specify both the user and drive in a filename.

e.g. "3B:TEST.BIN" is valid and will try to find TEST.BIN in user 3 of drive B.

VDOS doesn't allow this. VDOS only allows the drive to be specified.

e.g. "B:TEST.BIN".

Therefore it's recommended to use SELECT to specify the user.

  • VDOS will autoboot a file called "HELLO" if it exists on the disc. AMSDOS doesn't have this.




Manual (German)