v4.0/src/H/DPB.H

   1  struct DPBType {
   2         char     drive ;        /* physical drive number                   */
   3         char     unit ;         /* unit within device                      */
   4         unsigned cbSector ;     /* bytes per sector                        */
   5         char     mask ;         /* sectors/alloc unit - 1                  */
   6         char     shift ;        /* bit to shift                            */
   7         unsigned secFAT ;       /* sector number of first FAT              */
   8         char     cFAT ;         /* count of FATs                           */
   9         unsigned cDirEnt ;      /* count of root directory entries         */
  10         unsigned secData ;      /* first data sector                       */
  11         unsigned cCluster ;     /* max number of clusters on drive         */
  12         unsigned csecFAT ;      /* sectors in each FAT                     */
  13         unsigned secDir ;       /* first sector of root dir                */
  14         long     pDevice ;      /* pointer to device header                */
  15         char     media ;        /* last media in drive                     */
  16         char     fFirst ;       /* TRUE => media check needed              */
  17         long     nextDPB ;      /* pointer to next dpb                     */
  18         unsigned clusFree ;     /* cluster number of last alloc            */
  19         unsigned FreeCnt ;      /* count of free clusters, -1 if unk       */
  20 /*      char     SyncFlg ;      /* sync flags, (see below)                 */
  21         } ;
  22
  23 /*      Definitions of SyncFlg values from DPB.INC  */
  24
  25 #define DPB_ABUSY  1        /* some process is allocating clusters */
  26 #define DPB_AWANT  2        /* some process waiting to allocate    */
  27 #define DPB_FBUSY  4        /* some process is reading FAT         */
  28 #define DPB_FWANT  8        /* some process waiting to read FAT    */
  29
  30 \1a