VaraDOS

VaraDOS is a upgraded Version of ParaDOS, a DOS for 3½" drives, coded by Richard Wilson and initially marketed by Quantum Computing.

VaraDOS is a complete replacement for the standard 16 KB AMSDOS ROM.

The first 6 KB are a patched version of the standard AMSDOS code, with the remaining 10 KB used for the large-format patch code and a disc utility (accessed by the |DRIVE command without any parameters).

Unlike ParaDOS the altered VaraDOS does support the Vortex format, which can be considered the standard format for 80 Track doublesided disc at least in some counties (Austria, Germany f.e.).

• Finally it got a checksum at address &FFFF like most expansion ROMs do
• The Vortex format (704 KB free space) is preselected for drive B
• The initialization message has been adapted
• The headline in the |DRIVE utility has been adapted
• Drive parameters have been adapted to Vortex format
• The letters VX indicate the usage of Vortex format

• ParaDOS Manual (pdf)
• ParaDOS DDB and DPB documentation (txt)