Int 78 Fn 04  - Targa.dev - Set Scsi Device Number                         [d]

   AH = 04h
   AL = SCSI device number

Return: CF set on error
   AL = error code (see #3457)

Note:  if this routine is not called, the device number used is the driver's
     default (usually 0)

See Also: AH=02h,AH=05h