MD_SETPARMS

set track and sector layout.

This defines the track and sector layout the mfm.device shall use for reading and writing to disk. Typically, applications will retrieve this layout from the MS-DOS bootblock of the disk.

The disk geometry is taken from a struct DosEnvec that is typically used to mount devices. The following entries are recognized:

de_HighCyl

defines the number of tracks on the disk - 1

de_DosType

if set to MDD\0, the drive is double-stepped, i.e. each track step command steps over two tracks. The number of tracks is then computed as (de_HighCyl+1)/2.

de_SizeBlock

Number of longs per sector, i.e. 128 longs = 512 bytes per sector.

de_SecOrg

Sector index of the first sector in the track. Normally 0.

de_Surfaces

Defines whether the disk is single or double sided. Must be 1 or 2.

de_BlocksPerTrack

Number of sectors(!) per track.

io_Device

preset by the call to OpenDevice()

io_Unit

preset by the call to OpenDevice()

io_Command

MD_SETPARMS

io_Flags

0

io_Length

ignored

io_Data

pointer to a struct DosEnvec, see <dos/filehandler.h>

io_Error

0 for success, or an error code as defined in <devices/trackdisk.h>

TD_ADDCHANGEINT, <devices/trackdisk.h>, <dos/filehandler.h>