UNIDRIVE-128 is (c) Copyright 1986 by Frank Prindle.  This program may be
freely distributed in both source and object form, but may not be sold for
profit.

UNIDRIVE-128 is a utility for the Commodore 128 running CP/M Plus, with one
or more Commodore 1571 disk drives.  UNIDRIVE-128 enhances the C-128 CP/M
implementation by allowing the 1571 disk drive(s) to read or write CP/M 5.25"
MFM disk formats other than the seven MFM formats supported by the standard
Commodore supplied BIOS.

UNIDRIVE-128 is menu driven and simple to use; select the MFM format(s) to
be supported (up to 10) by pressing the menu letter, then press RETURN to
enable use of those formats.  The standard 7 formats are pre-selected, but
may be de-selected by pressing their menu letter if more than 3 additional
formats are required (not real likely).  To abort without changing the
current formats supported, press the ESCape key.

Once a set of formats have been selected and enabled, and UNIDRIVE-128 has
terminated, an MFM CP/M diskette in any of the selected formats may be
inserted into any 1571 drive on the system (including virtual drive E:) and
logged in.  If the diskette being logged could possibly be one of several
different formats selected, the Commodore BIOS will display a potential disk
format at the bottom of the screen; use the right arrow key to change this
display (if necessary) until the format displayed corresponds to the format
of the disk in the drive, then press RETURN.  If the diskette being logged
could only match one selected format, no menu selection will be required.  If
the diskette being logged does not match any selected format, "missing" will
be displayed and pressing RETURN will report a disk error.  When multiple
formats have been selected, each drive in the system may be logged in with a
different MFM format; the three Commodore GCR formats are unaffected and always
available.

Because the Commodore 128 BIOS already includes support for multiple MFM
diskette formats, UNIDRIVE-128 is a very simple program.  No part of the
program or any RSXs remain once it has terminated - all format translation
is handled by the BIOS in bank 0; none of the 58K TPA is lost for application
programs.

UNIDRIVE-128 Version 1.0 supports only 24 CP/M disk formats (chosen pretty
much at random) on one menu screen, and does not support diskette formatting.
Future versions will support many more formats, and will support formatting.
Only "double density" MFM formats are currently supported since it is not
known if the 1571 can read or write in single density (nor do I have a source
of single density diskettes with which to test); perhaps this will be ironed
out in future versions.

FCP (10 Nov 86)