Topic       : The ATARI Compendium
Author      : Scott Sanders / JAY Software
Version     : 1.25 (20/6/2003)
Subject     : Documentation
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Index Size  : 32614
HCP-Version : 6
Compiled on : Atari
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View Ref-FileFlopfmt()
Flopwr()
Protobt()                                                             XBIOS

Syntax

VOID Protobt( buf, serial, type, execflag )
VOIDP buf;
LONG serial;
WORD type, execflag;

Function      Protobt() creates a prototype floppy boot sector in memory
              for writing to a floppy drive.

Opcode        18 (0x12)

Availability  All TOS versions.

Parameters    buf is a 512 byte long buffer where the prototyped buffer
              will be written. If you are creating an executable boot
              sector, the memory buffer should contain the code you
              require. serial can be any of the following values:

              Name              serial         Meaning

              SERIAL_NOCHANGE   -1             Don't change the serial
                                               number already in memory.

              SERIAL_RANDOM     >0x01000000    Use a random number for the
                                               serial number

              -                 any other      Set the serial number to
                                positive       serial.
                                 number

              type defines the type of disk to prototype as follows:

              Name              type    Meaning

              DISK_NOCHANGE     -1      Don't change disk type.

              DISK_SSSD          0      40 Track, Single-Sided (180K)

              DISK_DSSD          1      40 Track, Double-Sided (360K)

              DISK_SSDD          2      80 Track, Single-Sided (360K)

              DISK_DSDD          3      80 Track, Double-Sided (720K)

              DISK_DSHD          4      High Density (1.44MB)

              DISK_DSED          5      Extra-High Density (2.88MB)

              execflag specifies the executable status of the boot sector as
              follows:

              Name           execflag   Meaning

              EXEC_NOCHANGE     -1      Don't alter executable status

              EXEC_NO            0      Disk is not executable

              EXEC_YES           1      Disk is executable

Binding       move.w   execflag,-(sp)
              move.w   type,-(sp)
              move.l   serial,-(sp)
              pea      buf
              move.w   #$12,-(sp)
              trap     #14
              lea      14(sp),sp

Caveats       type values of DISK_DSHD and DISK_DSED are only available when
              the high byte of the '_FDC' cookie has a value of FLOPPY_DSHD
              (1) and FLOPPY_DSED (2) respectively.

Comments      To create an MS-DOS compatible disk you must set the first
              three bytes of the prototyped boot sector to 0xE9, 0x00, and
              0x4E.

See Also      Flopfmt(), Flopwr()