v4.0/src/INC/DPB.INC

   1 ;       SCCSID = @(#)dpb.asm    1.1 85/04/10
   2 ;       SCCSID = @(#)dpb.asm    1.1 85/04/10
   3 BREAK <DPB structure>
   4 ;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
   5 ;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
   6 ;                                                                          ;
   7 dpb     STRUC
   8 dpb_drive           DB      ?           ; Logical drive # assoc with DPB (A=0,B=1,...)
   9 dpb_UNIT            DB      ?           ; Driver unit number of DPB
  10 dpb_sector_size     DW      ?           ; Size of physical sector in bytes
  11 dpb_cluster_mask    DB      ?           ; Sectors/cluster - 1
  12 dpb_cluster_shift   DB      ?           ; Log2 of sectors/cluster
  13 dpb_first_FAT       DW      ?           ; Starting record of FATs
  14 dpb_FAT_count       DB      ?           ; Number of FATs for this drive
  15 dpb_root_entries    DW      ?           ; Number of directory entries
  16 dpb_first_sector    DW      ?           ; First sector of first cluster
  17 dpb_max_cluster     DW      ?           ; Number of clusters on drive + 1
  18 dpb_FAT_size        DW      ?           ;;Number of records occupied by FAT
  19 dpb_dir_sector      DW      ?           ; Starting record of directory
  20 dpb_driver_addr     DD      ?           ; Pointer to driver
  21 dpb_media           DB      ?           ; Media byte
  22 dpb_first_access    DB      ?           ; This is initialized to -1 to force a media
  23                                         ; check the first time this DPB is used
  24 dpb_next_dpb        DD      ?           ; Pointer to next Drive parameter block
  25 dpb_next_free       DW      ?           ; Cluster # of last allocated cluster
  26 dpb_free_cnt        DW      ?           ; Count of free clusters, -1 if unknown
  27 dpb     ENDS
  28
  29 DPBSIZ  EQU     SIZE dpb                ; Size of the structure in bytes
  30
  31 DSKSIZ  =       dpb_max_cluster         ; Size of disk (temp used during init only)
  32 ;                                                                          ;
  33 ;            C  A  V  E  A  T     P  R  O  G  R  A  M  M  E  R             ;
  34 ;----+----+----+----+----+----+----+----+----+----+----+----+----+----+----;
  35 \1a