{ -----------------------------------------------------------------------------

                                 NOTICE:

      THESE MATERIALS are UNSUPPORTED by OSS!  If you do not understand how to
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      THE BOTTOM LINE:

         Use it, enjoy it, but you are on your own when using these materials!


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Introduction                                                            Page 1

                Introduction to BIOS, XBIOS, and GEMDOS Calls

Not all of the hardware and software utilities of the ST computer are directly
supported by standard Pascal operations.  Personal Pascal allows you to access
such machine-specific operations by giving you access to the BIOS, the Xtended
BIOS,  and  the  GEMDOS  systems.  These three pieces of software allow you to
control the ST hardware and perform disk operations not directly supported  by
standard Pascal.  The Personal Pascal compiler is smart enough to generate the
proper  code  to  access these routines, providing you tell it what parameters
those routines are expecting.  This documentation will provide you with enough
information to write Pascal programs that call the BIOS, XBIOS, or GEMDOS.

Since there are so many calls available in  those  three  subsystems,  we  are
splitting  the  description  of  the  calls into several sections.  Not all of
those sections will be available right away, but we will  be  steadily  adding
documentation so we can have a complete set as soon as possible.  The sections
of documentation that will be available are:

  Character oriented I/O
  Disk file I/O
  Hardware port configuration
  Time and date functions
  Sound generation
  Directories and paths
  Directory searching
  Graphics hardware
  Miscellaneous

In addition, a numerical list of all BIOS, XBIOS, and GEMDOS calls, with their
appropriate Pascal bindings, will be available at a later date.

We also recommend purchasing the book "Atari ST Internals", from Abacus books.
Not  all of the information contained there is accurate, but most is, and much
more information is available there than we can hope to provide.