--
--****************************************************************************
--*                                                                          *
--*  Copyright (c) 2001                                                      *
--*  by DIGITAL Equipment Corporation, Maynard, Mass.                        *
--*                                                                          *
--*  This software is furnished under a license and may be used and  copied  *
--*  only  in  accordance  with  the  terms  of  such  license and with the  *
--*  inclusion of the above copyright notice.  This software or  any  other  *
--*  copies  thereof may not be provided or otherwise made available to any  *
--*  other person.  No title to and ownership of  the  software  is  hereby  *
--*  transferred.                                                            *
--*                                                                          *
--*  The information in this software is subject to change  without  notice  *
--*  and  should  not  be  construed  as  a commitment by DIGITAL Equipment  *
--*  Corporation.                                                            *
--*                                                                          *
--*  DIGITAL assumes no responsibility for the use or  reliability  of  its  *
--*  software on equipment which is not supplied by DIGITAL.                 *
--*                                                                          *
--****************************************************************************
--********************************************************************************************************************
-- Created: 15-MAR-2001 22:51:57 by OpenVMS SDL EV1-33     
-- Source:   9-MAY-1997 06:51:30 $11$DUA933:[LIB_ADA.LIS]FCBDEF.SDL;1 
--********************************************************************************************************************
with SYSTEM; use SYSTEM;
with STARLET; use STARLET;
with CONDITION_HANDLING; use CONDITION_HANDLING;
 
package FCBDEF is
 
--  module $FCBDEF
 
--+
-- FCB - FILE CONTROL BLOCK
--
-- THERE IS ONE FILE CONTROL BLOCK FOR EACH UNIQUELY ACCESSED FILE ON A
-- VOLUME. THE FILE CONTROL BLOCK PROVIDES THE VEHICLE WHEREBY SHARED
-- ACCESS TO A FILE MAY BE CONTROLLED.
---
 
    FCB_M_FILE_ATTRIBUTES	: constant := 16#0000000F#;
    FCB_M_FILE_CONTENTS		: constant := 16#000000F0#;
    FCB_M_FLUSH_ON_CLOSE	: constant := 16#00000F00#;
    FCB_M_CACHING_OPTIONS_MBZ	: constant := 16#FFFFF000#;
    FCB_C_DEFAULT		: constant := 0;			--  Use default caching policy
    FCB_C_WRITETHROUGH		: constant := 1;			--  Use writethrough caching
    FCB_C_WRITEBEHIND		: constant := 2;			--  Use writebehind caching
    FCB_C_NOCACHING		: constant := 3;			--  Do not cache file
    FCB_C_FLUSH			: constant := 1;			--  Flush file from cache when file closed
    FCB_C_NOFLUSH		: constant := 2;			--  Retain file in cache when file closed
    FCB_M_VCC_STATE		: constant := 16#00000007#;
    FCB_K_LENGTH		: constant := 296;			--  LENGTH OF STANDARD FCB 
    FCB_C_LENGTH		: constant := 296;			--  LENGTH OF STANDARD FCB 
 
    type FCB_STATUS_TYPE is						--  FILE STATUS 
	record
	    DIR		: BOOLEAN;					--  FCB IS A DIRECTORY LRU ENTRY 
	    MARKDEL	: BOOLEAN;					--  FILE IS MARKED FOR DELETE 
	    BADBLK	: BOOLEAN;					--  BAD BLOCK ENCOUNTERED IN FILE 
	    EXCL	: BOOLEAN;					--  FILE IS EXCLUSIVELY ACCESSED 
	    SPOOL	: BOOLEAN;					--  FILE IS AN INTERMEDIATE SPOOL FILE 
	    RMSLOCK	: BOOLEAN;					--  FILE IS OPEN WITH RMS RECORD LOCKING 
	    ERASE	: BOOLEAN;					--  ERASE DATA WHEN BLOCKS REMOVED FROM FILE
	    BADACL	: BOOLEAN;					--  ACL IS CORRUPT
	    STALE	: BOOLEAN;					--  Reconstruct FCB from header.
	    DELAYTRNC	: BOOLEAN;					--  Delay truncation.
	    LIMBO	: BOOLEAN;					--  FCB is linked into the LIMBO queue
	    ISDIR	: BOOLEAN;					--  This FCB is a directory FCB
	    NOMOVE	: BOOLEAN;					--  This file is NOT to be MOVEFILE'ed
	    SHELVED	: BOOLEAN;					--  This file is shelved
	    NOSHELVABLE	: BOOLEAN;					--  This file shouldn't ever be shelved 
	    PRESHELVED	: BOOLEAN;					--  This file has been shelved, but
									--  the data has not been erased from disk
	end record;
 
	    for FCB_STATUS_TYPE use 
		record
		    DIR		at 0 range 0 .. 0;
		    MARKDEL	at 0 range 1 .. 1;
		    BADBLK	at 0 range 2 .. 2;
		    EXCL	at 0 range 3 .. 3;
		    SPOOL	at 0 range 4 .. 4;
		    RMSLOCK	at 0 range 5 .. 5;
		    ERASE	at 0 range 6 .. 6;
		    BADACL	at 0 range 7 .. 7;
		    STALE	at 1 range 0 .. 0;
		    DELAYTRNC	at 1 range 1 .. 1;
		    LIMBO	at 1 range 2 .. 2;
		    ISDIR	at 1 range 3 .. 3;
		    NOMOVE	at 1 range 4 .. 4;
		    SHELVED	at 1 range 5 .. 5;
		    NOSHELVABLE	at 1 range 6 .. 6;
		    PRESHELVED	at 1 range 7 .. 7;
		end record;
	    for FCB_STATUS_TYPE'SIZE use 16;
 
    FCB_STATUS_TYPE_INIT : constant FCB_STATUS_TYPE := 
	    (DIR	=> FALSE,
	    MARKDEL	=> FALSE,
	    BADBLK	=> FALSE,
	    EXCL	=> FALSE,
	    SPOOL	=> FALSE,
	    RMSLOCK	=> FALSE,
	    ERASE	=> FALSE,
	    BADACL	=> FALSE,
	    STALE	=> FALSE,
	    DELAYTRNC	=> FALSE,
	    LIMBO	=> FALSE,
	    ISDIR	=> FALSE,
	    NOMOVE	=> FALSE,
	    SHELVED	=> FALSE,
	    NOSHELVABLE	=> FALSE,
	    PRESHELVED	=> FALSE);
 
    type FCB_FID_RVN_TYPE is						--  RELATIVE VOLUME NUMBER 
	record
	    FID_RVN	: UNSIGNED_BYTE;				--  SHORT FORM RVN 
	    FID_NMX	: UNSIGNED_BYTE;				--  EXTENDED FILE NUMBER 
	end record;
 
	    for FCB_FID_RVN_TYPE use 
		record
		    FID_RVN	at 0 range 0 .. 7;
		    FID_NMX	at 1 range 0 .. 7;
		end record;
	    for FCB_FID_RVN_TYPE'SIZE use 16;
 
    FCB_FID_RVN_TYPE_INIT : constant FCB_FID_RVN_TYPE := 
	    (FID_RVN	=> 0,
	    FID_NMX	=> 0);
 
    type FCB_FID_ISO_9660_FIELDS_TYPE is				--  File ID fields for ISO 9660
	record
	    FID_DIRNUM	: UNSIGNED_WORD;				--       Directory number of File-Id
	    FID_RECNUM	: UNSIGNED_LONGWORD;				--       Record number of File-ID
	end record;
 
	    for FCB_FID_ISO_9660_FIELDS_TYPE use 
		record
		    FID_DIRNUM	at 0 range 0 .. 15;
		    FID_RECNUM	at 2 range 0 .. 31;
		end record;
	    for FCB_FID_ISO_9660_FIELDS_TYPE'SIZE use 48;
 
    FCB_FID_ISO_9660_FIELDS_TYPE_INIT : constant FCB_FID_ISO_9660_FIELDS_TYPE := 
	    (FID_DIRNUM	=> 0,
	    FID_RECNUM	=> 0);
 
    type FCB_FID_COMPONENT_TYPE is					--  FILE IDENTIFICATION 
	record
	    FID_NUM	: UNSIGNED_WORD;				--  FILE NUMBER 
	    FID_SEQ	: UNSIGNED_WORD;				--  FILE SEQUENCE NUMBER 
	    FID_RVN	: FCB_FID_RVN_TYPE;				--  RELATIVE VOLUME NUMBER 
 
	    ----Component(s) below are defined as comments since they
	    ----overlap other fields
	    ----
	    ----FID_ISO_9660_FIELDS	: FCB_FID_ISO_9660_FIELDS_TYPE;	--  File ID fields for ISO 9660
 
	end record;
 
	    for FCB_FID_COMPONENT_TYPE use 
		record
		    FID_NUM	at 0 range 0 .. 15;
		    FID_SEQ	at 2 range 0 .. 15;
		    FID_RVN	at 4 range 0 .. 15;
 
		    ----Component representation spec(s) below are defined as
		    ----comments since they overlap other fields
		    ----
		    ----FID_ISO_9660_FIELDS	at 0 range 0 .. 47;
 
		end record;
	    for FCB_FID_COMPONENT_TYPE'SIZE use 48;
 
    FCB_FID_COMPONENT_TYPE_INIT : constant FCB_FID_COMPONENT_TYPE := 
	    (FID_NUM	=> 0,
	    FID_SEQ	=> 0,
	    FID_RVN	=> FCB_FID_RVN_TYPE_INIT
	    );
 
    TYPE FCB_FID_TYPE is
	ARRAY (1 .. 3) of FCB_FID_COMPONENT_TYPE;
 
    FCB_FID_TYPE_INIT : constant FCB_FID_TYPE := 
	( others => FCB_FID_COMPONENT_TYPE_INIT);
 
    type FCB_LIMBOQHD_TYPE is						--  LIMBO queue header
	record
	    LIMBOFL	: UNSIGNED_LONGWORD;				--  Highwater mark update queue
	    LIMBOBL	: UNSIGNED_LONGWORD;				--  Highwater mark update queue
	end record;
 
	    for FCB_LIMBOQHD_TYPE use 
		record
		    LIMBOFL	at 0 range 0 .. 31;
		    LIMBOBL	at 4 range 0 .. 31;
		end record;
	    for FCB_LIMBOQHD_TYPE'SIZE use 64;
 
    FCB_LIMBOQHD_TYPE_INIT : constant FCB_LIMBOQHD_TYPE := 
	    (LIMBOFL	=> 0,
	    LIMBOBL	=> 0);
 
    type FCB_QUEUE_OVERLAY_TYPE is
	record
	    HWM_WAITFL	: UNSIGNED_LONGWORD;				--  Highwater mark update queue
	    HWM_WAITBL	: UNSIGNED_LONGWORD;				--  Highwater mark update queue
 
	    ----Component(s) below are defined as comments since they
	    ----overlap other fields
	    ----
	    ----LIMBOQHD	: FCB_LIMBOQHD_TYPE;			--  LIMBO queue header
 
	end record;
 
	    for FCB_QUEUE_OVERLAY_TYPE use 
		record
		    HWM_WAITFL	at 0 range 0 .. 31;
		    HWM_WAITBL	at 4 range 0 .. 31;
 
		    ----Component representation spec(s) below are defined as
		    ----comments since they overlap other fields
		    ----
		    ----LIMBOQHD	at 0 range 0 .. 63;
 
		end record;
	    for FCB_QUEUE_OVERLAY_TYPE'SIZE use 64;
 
    FCB_QUEUE_OVERLAY_TYPE_INIT : constant FCB_QUEUE_OVERLAY_TYPE := 
	    (HWM_WAITFL	=> 0,
	    HWM_WAITBL	=> 0);
 
    type FCB_FILEOWNER_TYPE is						--  FILE OWNER UIC 
	record
	    UICMEMBER	: UNSIGNED_WORD;				--  MEMBER NUMBER 
	    UICGROUP	: UNSIGNED_WORD;				--  GROUP NUMBER 
	end record;
 
	    for FCB_FILEOWNER_TYPE use 
		record
		    UICMEMBER	at 0 range 0 .. 15;
		    UICGROUP	at 2 range 0 .. 15;
		end record;
	    for FCB_FILEOWNER_TYPE'SIZE use 32;
 
    FCB_FILEOWNER_TYPE_INIT : constant FCB_FILEOWNER_TYPE := 
	    (UICMEMBER	=> 0,
	    UICGROUP	=> 0);
 
    type FCB_SYS_PROT_TYPE is						--  Protection word/vector
	record
	    FILEPROT	: UNSIGNED_WORD;				--  FILE PROTECTION MASK 
	    FILLER_1	: UNSIGNED_WORD;
	end record;
 
	    for FCB_SYS_PROT_TYPE use 
		record
		    FILEPROT	at 0 range 0 .. 15;
		    FILLER_1	at 2 range 0 .. 15;
		end record;
	    for FCB_SYS_PROT_TYPE'SIZE use 32;
 
    FCB_SYS_PROT_TYPE_INIT : constant FCB_SYS_PROT_TYPE := 
	    (FILEPROT	=> 0,
	    FILLER_1	=> 0);
 
    type FCB_MIN_CLASS_PROT_TYPE is					--  Minimum security classification mask
	record
	    FILLER_1	: UNSIGNED_BYTE_ARRAY (1 .. 20);		--  see structure $CLSDEF
	end record;
 
	    for FCB_MIN_CLASS_PROT_TYPE use 
		record
		    FILLER_1	at 0 range 0 .. 159;
		end record;
	    for FCB_MIN_CLASS_PROT_TYPE'SIZE use 160;
 
    FCB_MIN_CLASS_PROT_TYPE_INIT : constant FCB_MIN_CLASS_PROT_TYPE := 
	    (FILLER_1	=> (others => 0));
 
    type FCB_MAX_CLASS_PROT_TYPE is					--  Maximum security classification mask
	record
	    FILLER_1	: UNSIGNED_BYTE_ARRAY (1 .. 20);		--  see structure $CLSDEF
	end record;
 
	    for FCB_MAX_CLASS_PROT_TYPE use 
		record
		    FILLER_1	at 0 range 0 .. 159;
		end record;
	    for FCB_MAX_CLASS_PROT_TYPE'SIZE use 160;
 
    FCB_MAX_CLASS_PROT_TYPE_INIT : constant FCB_MAX_CLASS_PROT_TYPE := 
	    (FILLER_1	=> (others => 0));
 
    type FCB_ORB_TYPE is						--  Object's Rights Block
	record
	    FILEOWNER	: FCB_FILEOWNER_TYPE;				--  FILE OWNER UIC 
	    FILLER_1	: UNSIGNED_LONGWORD;				--  ACL mutex
	    FILLER_2	: UNSIGNED_LONGWORD;				--  Structure size & type
	    FILLER_3	: UNSIGNED_LONGWORD;				--  Spare + ref count
	    ACMODE	: UNSIGNED_QUADWORD;				--  Access mode protection vector
	    SYS_PROT	: FCB_SYS_PROT_TYPE;				--  Protection word/vector
	    OWN_PROT	: UNSIGNED_LONGWORD;				--  Owner protection
	    GRP_PROT	: UNSIGNED_LONGWORD;				--  Group protection
	    WOR_PROT	: UNSIGNED_LONGWORD;				--  World protection
	    ACLFL	: UNSIGNED_LONGWORD;				--  ACCESS CONTROL LIST FORWARD LINK 
	    ACLBL	: UNSIGNED_LONGWORD;				--  ACCESS CONTROL LIST BACKWARD LINK 
	    MIN_CLASS_PROT	: FCB_MIN_CLASS_PROT_TYPE;		--  Minimum security classification mask
	    MAX_CLASS_PROT	: FCB_MAX_CLASS_PROT_TYPE;		--  Maximum security classification mask
	    FILLER_4	: UNSIGNED_WORD;
	    FILLER_5	: UNSIGNED_WORD;
	    FILLER_6	: UNSIGNED_LONGWORD;
	    FILLER_7	: UNSIGNED_LONGWORD;
	    FILLER_8	: UNSIGNED_LONGWORD;
	    FILLER_9	: UNSIGNED_LONGWORD;
	    FILLER_10	: UNSIGNED_LONGWORD;
	    FILLER_11	: UNSIGNED_WORD;
	    FILLER_12	: UNSIGNED_WORD;
	    FILLER_13	: UNSIGNED_LONGWORD;
	    FILLER_14	: UNSIGNED_LONGWORD;
	end record;
 
	    for FCB_ORB_TYPE use 
		record
		    FILEOWNER	at 0 range 0 .. 31;
		    FILLER_1	at 4 range 0 .. 31;
		    FILLER_2	at 8 range 0 .. 31;
		    FILLER_3	at 12 range 0 .. 31;
		    ACMODE	at 16 range 0 .. 63;
		    SYS_PROT	at 24 range 0 .. 31;
		    OWN_PROT	at 28 range 0 .. 31;
		    GRP_PROT	at 32 range 0 .. 31;
		    WOR_PROT	at 36 range 0 .. 31;
		    ACLFL	at 40 range 0 .. 31;
		    ACLBL	at 44 range 0 .. 31;
		    MIN_CLASS_PROT	at 48 range 0 .. 159;
		    MAX_CLASS_PROT	at 68 range 0 .. 159;
		    FILLER_4	at 88 range 0 .. 15;
		    FILLER_5	at 90 range 0 .. 15;
		    FILLER_6	at 92 range 0 .. 31;
		    FILLER_7	at 96 range 0 .. 31;
		    FILLER_8	at 100 range 0 .. 31;
		    FILLER_9	at 104 range 0 .. 31;
		    FILLER_10	at 108 range 0 .. 31;
		    FILLER_11	at 112 range 0 .. 15;
		    FILLER_12	at 114 range 0 .. 15;
		    FILLER_13	at 116 range 0 .. 31;
		    FILLER_14	at 120 range 0 .. 31;
		end record;
	    for FCB_ORB_TYPE'SIZE use 992;
 
    FCB_ORB_TYPE_INIT : constant FCB_ORB_TYPE := 
	    (
	    FILEOWNER	=> FCB_FILEOWNER_TYPE_INIT,
	    FILLER_1	=> 0,
	    FILLER_2	=> 0,
	    FILLER_3	=> 0,
	    ACMODE	=> (0, 0),
	    SYS_PROT	=> FCB_SYS_PROT_TYPE_INIT,
	    OWN_PROT	=> 0,
	    GRP_PROT	=> 0,
	    WOR_PROT	=> 0,
	    ACLFL	=> 0,
	    ACLBL	=> 0,
	    MIN_CLASS_PROT	=> FCB_MIN_CLASS_PROT_TYPE_INIT,
	    MAX_CLASS_PROT	=> FCB_MAX_CLASS_PROT_TYPE_INIT,
	    FILLER_4	=> 0,
	    FILLER_5	=> 0,
	    FILLER_6	=> 0,
	    FILLER_7	=> 0,
	    FILLER_8	=> 0,
	    FILLER_9	=> 0,
	    FILLER_10	=> 0,
	    FILLER_11	=> 0,
	    FILLER_12	=> 0,
	    FILLER_13	=> 0,
	    FILLER_14	=> 0);
 
    type FCB_CACHING_OPTIONS_TYPE is
	record
	    FILE_ATTRIBUTES	: UNSIGNED_4;				--  File attributes caching field
	    FILE_CONTENTS	: UNSIGNED_4;				--  File contents caching field
	    FLUSH_ON_CLOSE	: UNSIGNED_4;				--  Flush file on close field
	    CACHING_OPTIONS_MBZ	: UNSIGNED_20;				--  Must be zero
	end record;
 
	    for FCB_CACHING_OPTIONS_TYPE use 
		record
		    FILE_ATTRIBUTES	at 0 range 0 .. 3;
		    FILE_CONTENTS	at 0 range 4 .. 7;
		    FLUSH_ON_CLOSE	at 1 range 0 .. 3;
		    CACHING_OPTIONS_MBZ	at 1 range 4 .. 23;
		end record;
	    for FCB_CACHING_OPTIONS_TYPE'SIZE use 32;
 
    FCB_CACHING_OPTIONS_TYPE_INIT : constant FCB_CACHING_OPTIONS_TYPE := 
	    (FILE_ATTRIBUTES	=> 0,
	    FILE_CONTENTS	=> 0,
	    FLUSH_ON_CLOSE	=> 0,
	    CACHING_OPTIONS_MBZ	=> 0);
 
    type FCB_STATUS2_TYPE is						--  Additional file status
	record
	    VCC_STATE	: UNSIGNED_3;					--  Replicated caching attribute (see FH2DEF)
	    FILLER_1	: UNSIGNED_29;
	end record;
 
	    for FCB_STATUS2_TYPE use 
		record
		    VCC_STATE	at 0 range 0 .. 2;
		    FILLER_1	at 0 range 3 .. 31;
		end record;
	    for FCB_STATUS2_TYPE'SIZE use 32;
 
    FCB_STATUS2_TYPE_INIT : constant FCB_STATUS2_TYPE := 
	    (VCC_STATE	=> 0,
	    FILLER_1	=> 0);
 
    type FCB_FILL_10_COMPONENT_TYPE is					--  ORB expansion space
	record
	    FILLER_1	: UNSIGNED_BYTE_ARRAY (1 .. 24);		--  Add new fields at end of expansion space
	    CFB		: UNSIGNED_QUADWORD;
	    CACHING_OPTIONS	: FCB_CACHING_OPTIONS_TYPE;
	    STATUS2	: FCB_STATUS2_TYPE;				--  Additional file status
	end record;
 
	    for FCB_FILL_10_COMPONENT_TYPE use 
		record
		    FILLER_1	at 0 range 0 .. 191;
		    CFB		at 24 range 0 .. 63;
		    CACHING_OPTIONS	at 32 range 0 .. 31;
		    STATUS2	at 36 range 0 .. 31;
		end record;
	    for FCB_FILL_10_COMPONENT_TYPE'SIZE use 320;
 
    FCB_FILL_10_COMPONENT_TYPE_INIT : constant FCB_FILL_10_COMPONENT_TYPE := 
	    (FILLER_1	=> (others => 0),
	    CFB		=> (0, 0),
	    CACHING_OPTIONS	=> FCB_CACHING_OPTIONS_TYPE_INIT,
	    STATUS2	=> FCB_STATUS2_TYPE_INIT
	    );
 
    TYPE FCB_FILL_10_TYPE is
	ARRAY (1 .. 40) of FCB_FILL_10_COMPONENT_TYPE;
 
    FCB_FILL_10_TYPE_INIT : constant FCB_FILL_10_TYPE := 
	( others => FCB_FILL_10_COMPONENT_TYPE_INIT);
 
    type FCB_TYPE is
	record
	    FCBFL	: UNSIGNED_LONGWORD;				--  FCB LIST FORWARD LINK 
	    FCBBL	: UNSIGNED_LONGWORD;				--  FCB LIST BACKWARD LINK 
	    SIZE	: UNSIGNED_WORD;				--  SIZE OF FCB IN BYTES 
	    TYP		: UNSIGNED_BYTE;				--  STRUCTURE TYPE OF FCB 
	    ACCLKMODE	: UNSIGNED_BYTE;				--  Access lock mode.
	    EXFCB	: UNSIGNED_LONGWORD;				--  ADDRESS OF EXTENSION FCB 
	    WLFL	: UNSIGNED_LONGWORD;				--  WINDOW LISTHEAD FORWARD LINK 
	    WLBL	: UNSIGNED_LONGWORD;				--  WINDOW LISTHEAD BACKWARD LINK 
	    REFCNT	: UNSIGNED_WORD;				--  Total references to this FCB.
	    ACNT	: UNSIGNED_WORD;				--  FILE ACCESS COUNT 
	    WCNT	: UNSIGNED_WORD;				--  FILE WRITER COUNT 
	    LCNT	: UNSIGNED_WORD;				--  FILE LOCK COUNT 
	    TCNT	: UNSIGNED_WORD;				--  COUNT OF TRUNCATE LOCKS 
	    STATUS	: FCB_STATUS_TYPE;				--  FILE STATUS 
	    FID		: FCB_FID_COMPONENT_TYPE;			--  FILE IDENTIFICATION 
	    SEGN	: UNSIGNED_WORD;				--  FILE SEGMENT NUMBER 
	    STVBN	: UNSIGNED_LONGWORD;				--  STARTING VIRTUAL BLOCK NUMBER 
	    STLBN	: UNSIGNED_LONGWORD;				--  STARTING LOGICAL BLOCK NUMBER 
	    HDLBN	: UNSIGNED_LONGWORD;				--  LBN OF FILE HEADER 
	    FILESIZE	: UNSIGNED_LONGWORD;				--  FILE SIZE IN BLOCKS 
	    EFBLK	: UNSIGNED_LONGWORD;				--  END OF FILE VBN 
	    VERSIONS	: UNSIGNED_WORD;				--  MAXIMUM NUMBER OF VERSIONS IN DIRECTORY 
	    DIRINDX	: UNSIGNED_LONGWORD;				--  Directory index pointer
	    DIRSEQ	: UNSIGNED_WORD;				--  DIRECTORY USE SEQUENCE NUMBER 
	    ACCLKID	: UNSIGNED_LONGWORD;				--  Access lock ID.
	    LOCKBASIS	: UNSIGNED_LONGWORD;				--  Lock basis for this FCB.
	    TRUNCVBN	: UNSIGNED_LONGWORD;				--  VBN for delayed truncation. (Files-11 B)
 
	    ----Component(s) below are defined as comments since they
	    ----overlap other fields
	    ----
	    ----NUMEXTENTS	: UNSIGNED_LONGWORD;			--  Number of extents recorded  (Files-11 C/D)
 
	    CACHELKID	: UNSIGNED_LONGWORD;				--  Cache interlock lock ID
	    HIGHWATER	: UNSIGNED_LONGWORD;				--  HIGH WATER MARK IN FILE
	    NEWHIGHWATER	: UNSIGNED_LONGWORD;			--  Highwater mark of pending writes
	    HWM_UPDATE	: UNSIGNED_WORD;				--  Count of writes past highwater mark
	    HWM_ERASE	: UNSIGNED_WORD;				--  Count of writes starting past highwater mark
	    HWM_PARTIAL	: UNSIGNED_WORD;				--  Count of partially validated erase operations
	    REVISION	: UNSIGNED_WORD;				--  File revision
	    QUEUE_OVERLAY	: FCB_QUEUE_OVERLAY_TYPE;
									-- 
									--  NOTA BENE:
									-- 
									--   The following is an embedded ORB.  This structure should only be referenced
									--   through the FCB$L_ORB pointer (using ORB$ field names).  The existing (FCB)
									--   fields are left for source code and binary compatibility in privileged
									--   software that thinks it knows what an FCB and its ORB look like.
									--   
									--   Third-party developers would be well advised to remove all references to
									--   these FCB symbols as soon as possible.  You have been warned!
									--   
	    ORB		: FCB_ORB_TYPE;					--  Object's Rights Block
	    FILLER_1	: UNSIGNED_BYTE_ARRAY (1 .. 4);			--  quadword alignment
									--  
									--  This overlay must leave the following FCB$L_ORB field quadword aligned.
									--  Take care when changing sizes.
									-- 
	    FILL_10	: FCB_FILL_10_COMPONENT_TYPE;			--  ORB expansion space
									-- 
									--  We now return you to your regularly scheduled file control block.
									-- 
	    ORB		: UNSIGNED_LONGWORD;				--  Address of file ORB
	    CFCB	: UNSIGNED_LONGWORD;				--  VBN Cache pointer
	    DIRLCKID	: UNSIGNED_LONGWORD;				--  Support for directory
									--  cache invalidation
	    PRIMFCB	: UNSIGNED_LONGWORD;				--  Pointer to Primary FCB if
									--   this is an extension FCB
									--   else zero
	end record;
 
	    for FCB_TYPE use 
		record
		    FCBFL	at 0 range 0 .. 31;
		    FCBBL	at 4 range 0 .. 31;
		    SIZE	at 8 range 0 .. 15;
		    TYP		at 10 range 0 .. 7;
		    ACCLKMODE	at 11 range 0 .. 7;
		    EXFCB	at 12 range 0 .. 31;
		    WLFL	at 16 range 0 .. 31;
		    WLBL	at 20 range 0 .. 31;
		    REFCNT	at 24 range 0 .. 15;
		    ACNT	at 26 range 0 .. 15;
		    WCNT	at 28 range 0 .. 15;
		    LCNT	at 30 range 0 .. 15;
		    TCNT	at 32 range 0 .. 15;
		    STATUS	at 34 range 0 .. 15;
		    FID		at 36 range 0 .. 47;
		    SEGN	at 42 range 0 .. 15;
		    STVBN	at 44 range 0 .. 31;
		    STLBN	at 48 range 0 .. 31;
		    HDLBN	at 52 range 0 .. 31;
		    FILESIZE	at 56 range 0 .. 31;
		    EFBLK	at 60 range 0 .. 31;
		    VERSIONS	at 64 range 0 .. 15;
		    DIRINDX	at 66 range 0 .. 31;
		    DIRSEQ	at 70 range 0 .. 15;
		    ACCLKID	at 72 range 0 .. 31;
		    LOCKBASIS	at 76 range 0 .. 31;
		    TRUNCVBN	at 80 range 0 .. 31;
 
		    ----Component representation spec(s) below are defined as
		    ----comments since they overlap other fields
		    ----
		    ----NUMEXTENTS	at 80 range 0 .. 31;
 
		    CACHELKID	at 84 range 0 .. 31;
		    HIGHWATER	at 88 range 0 .. 31;
		    NEWHIGHWATER	at 92 range 0 .. 31;
		    HWM_UPDATE	at 96 range 0 .. 15;
		    HWM_ERASE	at 98 range 0 .. 15;
		    HWM_PARTIAL	at 100 range 0 .. 15;
		    REVISION	at 102 range 0 .. 15;
		    QUEUE_OVERLAY	at 104 range 0 .. 63;
		    ORB		at 112 range 0 .. 991;
		    FILLER_1	at 236 range 0 .. 31;
		    FILL_10	at 240 range 0 .. 319;
		    ORB		at 280 range 0 .. 31;
		    CFCB	at 284 range 0 .. 31;
		    DIRLCKID	at 288 range 0 .. 31;
		    PRIMFCB	at 292 range 0 .. 31;
		end record;
	    for FCB_TYPE'SIZE use 2368;
 
    FCB_TYPE_INIT : constant FCB_TYPE := 
	    (FCBFL	=> 0,
	    FCBBL	=> 0,
	    SIZE	=> 0,
	    TYP		=> 0,
	    ACCLKMODE	=> 0,
	    EXFCB	=> 0,
	    WLFL	=> 0,
	    WLBL	=> 0,
	    REFCNT	=> 0,
	    ACNT	=> 0,
	    WCNT	=> 0,
	    LCNT	=> 0,
	    TCNT	=> 0,
	    STATUS	=> FCB_STATUS_TYPE_INIT,
	    FID		=> FCB_FID_TYPE_INIT,
	    SEGN	=> 0,
	    STVBN	=> 0,
	    STLBN	=> 0,
	    HDLBN	=> 0,
	    FILESIZE	=> 0,
	    EFBLK	=> 0,
	    VERSIONS	=> 0,
	    DIRINDX	=> 0,
	    DIRSEQ	=> 0,
	    ACCLKID	=> 0,
	    LOCKBASIS	=> 0,
	    TRUNCVBN	=> 0,
	    CACHELKID	=> 0,
	    HIGHWATER	=> 0,
	    NEWHIGHWATER	=> 0,
	    HWM_UPDATE	=> 0,
	    HWM_ERASE	=> 0,
	    HWM_PARTIAL	=> 0,
	    REVISION	=> 0,
	    QUEUE_OVERLAY	=> FCB_QUEUE_OVERLAY_TYPE_INIT,
	    ORB		=> FCB_ORB_TYPE_INIT,
	    FILLER_1	=> (others => 0),
	    FILL_10	=> FCB_FILL_10_TYPE_INIT,
	    ORB		=> 0,
	    CFCB	=> 0,
	    DIRLCKID	=> 0,
	    PRIMFCB	=> 0);
 
end FCBDEF;