1657 lines
58 KiB
Plaintext
1657 lines
58 KiB
Plaintext
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MS-DOS 2.0
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System Calls Reference
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+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
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| |
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| C A V E A T P R O G R A M M E R |
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| |
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| Certain structures, constants and system calls below |
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| are private to the DOS and are extremely |
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| version-dependent. They may change at any time at the |
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| implementors' whim. As a result, they must not be |
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| documented to the general public. If an extreme case |
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| arises, they must be documented with this warning. |
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| |
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| Those structures and constants that are subject to the |
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| above will be marked and bracketed with the flag: |
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| |
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| C A V E A T P R O G R A M M E R |
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| |
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+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
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Section 1
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Extensions to existing call structure
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Name: * Alloc - allocate memory
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Assembler usage:
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MOV BX,size
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MOV AH,Alloc
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INT 21h
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; AX:0 is pointer to allocated memory
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; if alloc fails, BX is the largest block available
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Description:
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Alloc returns a pointer to a free block of memory
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that has the requested size in paragraphs.
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Error return:
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AX = error_not_enough_memory
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The largest available free block is smaller
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than that requested or there is no free block.
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= error_arena_trashed
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The internal consistency of the memory arena
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has been destroyed. This is due to a user
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program changing memory that does not belong
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to it.
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Name: * CharOper - change incompatible configuration
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parameters
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Assembler usage:
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MOV AH, CharOper
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MOV AL, func
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MOV DL, data
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INT 21h
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; on read functions, data is returned in DL
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Description:
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CharOper allows a program to change system
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parameters to allow for switch indicators and whether
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devices are available at every level of the directory
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tree.
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A function code is passed in AL:
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AL Function
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-- --------
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0 DL, on return, will contain the DOS switch
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character. On most systems this will default to
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'-'.
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1 Set the switch character to the character in DL.
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2 Read the device availability byte into DL. If
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this byte is 0, then devices must be accessed in
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file I/O calls by /dev/device. If this byte is
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non-zero, then the devices are available at every
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node of the directory tree (i.e. CON is the
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console device not the file CON). This byte is
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generally 0.
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3 Set the device availability byte to the value in
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DL.
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Error returns:
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AL = FF
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The function code specified in AL is not in
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the range 0:3
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Name: * CurrentDir - return text of current directory
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Assembler usage:
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MOV AH,CurrentDir
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LDS SI,area
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MOV DL,drive
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INT 21h
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; DS:SI is a pointer to 64 byte area that contains
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; drive current directory.
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Description:
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CurrentDir returns the current directory for a
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particular drive. The directory is root-relative and
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does not contain the drive specifier. The drive code
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passed in DL is 0=default, 1=A, 2=B, etc.
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Error returns:
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AX = error_invalid_drive
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The drive specified in DL was invalid.
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Name: * Dealloc - free allocated memory
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Assembler usage:
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MOV ES,block
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MOV AH,dealloc
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INT 21h
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Description:
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Dealloc returns a piece of memory to the system
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pool that was allocated by alloc.
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Error return:
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AX = error_invalid_block
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The block passed in ES is not one allocated
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via Alloc.
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= error_arena_trashed
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The internal consistency of the memory arena
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has been destroyed. This is due to a user
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program changing memory that does not belong
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to it.
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Name: * FileTimes - get/set the write times of a
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handle
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Assembler usage:
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MOV AH, FileTimes
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MOV AL, func
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MOV BX, handle
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; if AL = 1 then then next two are mandatory
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MOV CX, time
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MOV DX, date
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INT 21h
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; if AL = 0 then CX/DX has the last write time/date
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; for the handle.
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Description:
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FileTimes returns or sets the last-write time for
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a handle. These times are not recorded until the file
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is closed.
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A function code is passed in AL:
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AL Function
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-- --------
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0 Return the time/date of the handle in CX/DX
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1 Set the time/date of the handle to CX/DX
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Error returns:
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AX = error_invalid_function
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The function passed in AL was not in the range
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0:1.
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= error_invalid_handle
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The handle passed in BX was not currently
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open.
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Name: * FindFirst - find matching file
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Assembler usage:
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MOV AH, FindFirst
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LDS DX, pathname
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MOV CX, attr
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INT 21h
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; DMA address has datablock
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Description:
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FindFirst takes a pathname with wildcards in the
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last component (passed in DS:DX), a set of attributes
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(passed in CX) and attempts to find all files that
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match the pathname and have a subset of the required
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attributes. A datablock at the current DMA is written
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that contains information in the following form:
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find_buf STRUC
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+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
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| C A V E A T P R O G R A M M E R |
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| |
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find_buf_sattr DB ? ; attribute of search
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find_buf_drive DB ? ; drive of search
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find_buf_name DB 11 DUP (?); search name
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find_buf_LastEnt DW ? ; LastEnt
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find_buf_ThisDPB DD ? ; This DPB
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find_buf_DirStart DW ? ; DirStart
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| |
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| C A V E A T P R O G R A M M E R |
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+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
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find_buf_attr DB ? ; attribute found
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find_buf_time DW ? ; time
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find_buf_date DW ? ; date
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find_buf_size_l DW ? ; low(size)
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find_buf_size_h DW ? ; high(size)
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find_buf_pname DB 13 DUP (?) ; packed name
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find_buf ENDS
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To obtain the subsequent matches of the pathname,
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see the description of FindNext
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Error Returns:
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AX = error_file_not_found
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The path specified in DS:DX was an invalid
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path.
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= error_no_more_files
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There were no files matching this
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specification.
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Name: * FindNext - step through a directory matching
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files
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Assembler usage:
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; DMA points at area returned by find_first
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MOV AH, findnext
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INT 21h
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; next entry is at dma
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Description:
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FindNext finds the next matching entry in a
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directory. The current DMA address must point at a
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block returned by FindFirst (see FindFirst).
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Error Returns:
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AX = error_no_more_files
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There are no more files matching this pattern.
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Name: * GetDMA - get current DMA transfer address
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Assembler usage:
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MOV AH,GetDMA
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INT 21h
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; ES:BX has current DMA transfer address
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Description:
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Return DMA transfer address.
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Error returns:
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None.
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+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
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| C A V E A T P R O G R A M M E R |
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| |
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Name: * GetDSKPT(DL) - get pointer to drive parameter
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block
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Assembler usage:
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MOV AH,GetDSKPT
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INT 21h
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; DS:BX has address of drive parameter block
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Description:
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Return pointer to default drive parameter block.
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Error returns:
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None.
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Assembler usage:
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MOV DL,DrvNUM
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MOV AH,GetDSKPTDL
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INT 21h
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; DS:BX has address of drive parameter block
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Description:
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Return pointer to drive parameter block for drive
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designated in DL (0=Default, A=1, B=2 ...)
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Error returns:
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AL = FF
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The drive given in DL is invalid.
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| |
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| C A V E A T P R O G R A M M E R |
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+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
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Name: * GetFreespace - get Disk free space
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Assembler usage:
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MOV AH,GetFreespace
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MOV DL,Drive ;0 = default, A = 1
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INT 21h
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; BX = Number of free allocation units on drive
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; DX = Total number of allocation units on drive
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; CX = Bytes per sector
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; AX = Sectors per allocation unit
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Description:
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Return Free space on disk along with additional
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information about the disk.
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Error returns:
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AX = FFFF
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The drive number given in DL was invalid.
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NOTE: This call returns the same information in the same
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registers (except for the FAT pointer) as the get FAT
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pointer calls did in previous versions of the DOS.
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Name: * GetInDOSF - get DOS critical-section flag
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Assembler usage:
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MOV AH,GetInDOSF
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INT 21h
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; ES:BX has location of the flag
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MOV CritSEG, ES
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MOV CritOFF, BX
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...
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IntVec:
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MOV AX, DWORD PTR Crit
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CMP AX,0
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JZ DoFunc
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IRET
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DoFunc: ...
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Description:
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Return location of indos flag. On return ES:BX is
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the address of a byte memory cell inside the DOS. If
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used in an interrupt service routine, it indicates
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whether or not the DOS was interrupted in a critical
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section. If the cell was zero, then the DOS was not
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in a critical section and thus can be called by the
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interrupt routine. If the cell was non-zero, the DOS
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should be considered to be in an uninterruptable state
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and for reliability, no DOS calls should be given.
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Error returns:
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None.
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Name: * GetVector - get interrupt vector
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Assembler usage:
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MOV AH,GetVector
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MOV AL,interrupt
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INT 21h
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; ES:BX now has long pointer to interrupt routine
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Description:
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Return interrupt vector associated with an
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interrupt.
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Error returns:
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None.
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Name: * GetVerifyFlag - return current setting of the
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verify after write flag.
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Assembler usage:
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MOV AH,GetVerifyFlag
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INT 21h
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; AL is the current verify flag value
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Description:
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The current value of the verify flag is returned
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in AL.
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Error returns:
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None.
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Name: * GetVersion - get DOS version number
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Assembler usage:
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MOV AH,GetVersion
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INT 21h
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; AL is the major version number
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; AH is the minor version number
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; BH is the OEM number
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; BL:CX is the (24 bit) user number
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Description:
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Return MS-DOS version number. On return AL.AH
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will be the two part version designation, ie. for
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MS-DOS 1.28 AL would be 1 and AH would be 28. For pre
|
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1.28 DOS AL = 0. Note that version 1.1 is the same as
|
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1.10, not the same as 1.01.
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Error returns:
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None.
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Name: * International - return country dependent
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information
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Assembler usage:
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LDS DX, blk
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MOV AH, International
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MOV AL, func
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INT 21h
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Description:
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This call returns in the block of memory pointed
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to by DS:DX, the following information pertinent to
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international applications:
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+---------------------------+
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| WORD Date/time format |
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+---------------------------+
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| BYTE ASCIZ string |
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| currency symbol |
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+---------------------------+
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| BYTE ASCIZ string |
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| thousands separator |
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+---------------------------+
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| BYTE ASCIZ string decimal |
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| separator |
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+---------------------------+
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|
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The date/time format has the following values and
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meanings:
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0 - USA standard h:m:s m/d/y
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1 - Europe standard h:m:s d/m/y
|
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2 - Japan standard y/m/d h:m:s
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The value passed in AL is either 0 (for current
|
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country) or a country code (to be defined later.
|
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Currently the country code must be zero).
|
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|
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Error returns:
|
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AX = error_invalid_function
|
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The function passed in AL was not 0
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(currently).
|
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Name: * KeepProcess - terminate process and remain
|
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resident
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Assembler usage:
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MOV AL, exitcode
|
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MOV DX, parasize
|
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MOV AH, KeepProcess
|
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INT 21h
|
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|
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Description:
|
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This call terminates the current process and
|
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attempts to set the initial allocation block to a
|
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specific size in paragraphs. It will not free up any
|
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other allocation blocks belonging to that process.
|
||
The exit code passed in AX is retrievable by the
|
||
parent via Wait.
|
||
|
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Error Returns:
|
||
None.
|
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|
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|
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Name: * Rename - move a directory entry
|
||
|
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Assembler usage:
|
||
LDS DX, source
|
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LES DI, dest
|
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MOV AH, Rename
|
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INT 21h
|
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|
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Description:
|
||
Rename will attempt to rename a file into another
|
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path. The paths must be on the same device.
|
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|
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Error returns:
|
||
AX = error_file_not_found
|
||
The file name specifed by DS:DX was not found.
|
||
= error_not_same_device
|
||
The source and destination are on different
|
||
drives.
|
||
= error_access_denied
|
||
The path specified in DS:DX was a directory or
|
||
the file specified by ES:DI exists or the
|
||
destination directory entry could not be
|
||
created.
|
||
|
||
|
||
Name: * SetBlock - modify allocated blocks
|
||
|
||
Assembler usage:
|
||
MOV ES,block
|
||
MOV BX,newsize
|
||
MOV AH,setblock
|
||
INT 21h
|
||
; if setblock fails for growing, BX will have the
|
||
; maximum size possible
|
||
|
||
Description:
|
||
Setblock will attempt to grow/shrink an allocated
|
||
block of memory.
|
||
|
||
Error return:
|
||
AX = error_invalid_block
|
||
The block passed in ES is not one allocated
|
||
via Alloc.
|
||
= error_arena_trashed
|
||
The internal consistency of the memory arena
|
||
has been destroyed. This is due to a user
|
||
program changing memory that does not belong
|
||
to it.
|
||
= error_not_enough_memory
|
||
There was not enough free memory after the
|
||
specified block to satisfy the grow request.
|
||
|
||
|
||
Name: * SetCtrlCTrapping - turn on/off broad ^C
|
||
checking
|
||
|
||
Assembler usage:
|
||
MOV DL,val
|
||
MOV AH,SetCtrlCTrapping
|
||
MOV AL,func
|
||
INT 21h
|
||
; If AL was 0, then DL has the current value of the
|
||
; ^C check
|
||
|
||
Description:
|
||
MSDOS ordinarily checks for a ^C on the
|
||
controlling device only when doing a function 1-12
|
||
operation to that device. SetCtrlCTrapping allows the
|
||
user to expand this checking to include any system
|
||
call. For example, with the ^C trapping off, all disk
|
||
I/O will proceed without interruption while with ^C
|
||
trapping on, the ^C interrupt is given at the system
|
||
call that initiates the disk operation.
|
||
|
||
Error return:
|
||
AL = FF
|
||
The function passed in AL was not in the range
|
||
0:1.
|
||
|
||
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|
||
| C A V E A T P R O G R A M M E R |
|
||
| |
|
||
|
||
Name: * Set_OEM_Handler - set handler for OEM
|
||
specific INT 21H calls.
|
||
|
||
Assembler usage:
|
||
LDS DX,handler_address
|
||
MOV AH,Set_OEM_Handler
|
||
INT 21H
|
||
|
||
Description:
|
||
Set handler address for 0F9H-0FFH INT 21H system
|
||
calls to DS:DX. To return the 0F9H-0FFH calls to
|
||
the uninitialized state, give DS=DX=-1.
|
||
|
||
Error returns:
|
||
None.
|
||
|
||
Handler entry:
|
||
All registers as user set them when INT 21H
|
||
issued (including SS:SP). INT 21 return is on
|
||
stack, so the correct method for the OEM handler
|
||
to return to the user is to give an IRET. The
|
||
OEM handler is free to make any INT 21H system
|
||
call (including the 0F9H- 0FFH group if the OEM
|
||
handler is re-entrant).
|
||
|
||
|
||
The AH INT 21H function codes 0F8H through 0FFH are
|
||
reserved for OEM extensions to the INT 21H calling
|
||
convention. These calls have two states, initialized
|
||
and uninitialized. There will be one handler for all 7
|
||
(0F9-0FFH) functions. When the DOS is first
|
||
initialized, these calls are uninitialized. The AH=0F8H
|
||
call is the call which will set the handler address for
|
||
the 0F9-0FFH calls. If the 0F9-0FFH calls are
|
||
uninitialized, an attempt to call them results in the
|
||
normal invalid system call number return.
|
||
OEMs should NOT document the 0F8 call.
|
||
| |
|
||
| C A V E A T P R O G R A M M E R |
|
||
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
Section 2
|
||
|
||
XENIX-compatible system calls
|
||
|
||
|
||
|
||
Previous to version 2.0, MSDOS had a simple single
|
||
directory structure that sufficed for small (160k to 320K)
|
||
diskettes. As the need for hard disk support grows, and
|
||
as MSDOS 2.0 will support a wide variety of hard disks,
|
||
the need for better disk organization also grows. Merely
|
||
expanding the directory is not an effective solution;
|
||
doing a 'DIR' on a directory with 1000 files is not a
|
||
user-friendly characteristic.
|
||
|
||
People, by nature, think in hierarchical terms:
|
||
organization charts and family trees, for example. It
|
||
would be nice to allow users to organize their files on
|
||
disk in a similar manner. Consider the following:
|
||
|
||
In a particular business, both sales and accounting
|
||
share a computer with a large disk and the individual
|
||
employees use it for preparation of reports and
|
||
maintaining accounting information. One would naturally
|
||
view the organization of files on the disk in this
|
||
fashion:
|
||
|
||
+-disk-+
|
||
/ \
|
||
/ \
|
||
/ \
|
||
sales accounting
|
||
/ | | \
|
||
/ | | \
|
||
/ | | \
|
||
John Mary Steve Sue
|
||
/ | (A) | | | \
|
||
/ | | | | \
|
||
/ | | | | \
|
||
report accts. report accts. report report
|
||
receiv. receiv
|
||
|
||
In MSDOS 2.0 the user can arrange his files in such a
|
||
manner that files that are not part of his current task do
|
||
not interfere with that task. Pre-2.0 versions of MSDOS
|
||
has a single directory that contains files. MSDOS extends
|
||
this concept to allow a directory to contain both files
|
||
and directories and to introduce the notion of the
|
||
'current' directory.
|
||
|
||
To specify a filename, the user could use one of two
|
||
methods, either specify a path from the root node to the
|
||
file, or specify a path from the current node to the file.
|
||
A path is a series of directory names separated by '/' and
|
||
ending with a filename. A path that starts at the root
|
||
begins with a '/'.
|
||
|
||
There is a special directory entry in each directory,
|
||
denoted by '..' that is the parent of the directory. The
|
||
root directory's parent is itself (who created God?).
|
||
|
||
Using a directory structure like the hierarchy above,
|
||
and assuming that the current directory is at point (D),
|
||
to reference the report under John, the following are all
|
||
equivalent:
|
||
|
||
report
|
||
/sales/John/report
|
||
../John/report
|
||
|
||
To refer to the report under Mary, the following are
|
||
all equivalent:
|
||
|
||
../Mary/report
|
||
/sales/Mary/report
|
||
|
||
To refer to the report under Sue, the following are
|
||
all equivalent.
|
||
|
||
../../accounting/Sue/report
|
||
/accounting/Sue/report
|
||
|
||
There is no restriction in MSDOS 2.0 on the depth of a
|
||
tree (the length of the longest path from root to leaf)
|
||
except in the number of allocation units available. The
|
||
root directory will have a fixed number of entries, 64 for
|
||
the single sided diskettes to XXX for a large hard disk.
|
||
For non-root directories, there is no limit to the number
|
||
of files per directory excepting in the number of
|
||
allocation units available.
|
||
|
||
Old (pre-2.0) disks will appear to MSDOS 2.0 as having
|
||
only a root directory with files in it and no
|
||
subdirectories whatever.
|
||
|
||
Implementation of the tree-structure is simple. The
|
||
root directory is the pre-2.0 directory. Subdirectories
|
||
of the root have a special attribute set indicating that
|
||
they are directories. The subdirectories themselves are
|
||
files, linked through the FAT as usual. Their contents
|
||
are identical in character to the contents of the root
|
||
directory.
|
||
|
||
Pre-2.0 programs that use system calls not described
|
||
below will not be able to make use of files in other
|
||
directories. They will only be able to access files in
|
||
the current directory. This is no great loss of
|
||
functionality as users will aggregate their files into
|
||
sub-directories on basis of functionality; the files that
|
||
are being used will be found in the current directory.
|
||
Those that are not necessary for the current task will be
|
||
placed in other directories. Out of sight, out of mind.
|
||
|
||
There are also new attributes in 2.0. These and the
|
||
old attributes apply to the tree structured directories in
|
||
the following manner:
|
||
|
||
Attribute Meaning/Function Meaning/Function
|
||
for files for directories
|
||
|
||
volume_id Present at the root. Meaningless.
|
||
Only one file may have
|
||
this set.
|
||
|
||
directory Meaningless. Indicates that the
|
||
directory entry is a
|
||
directory. Cannot be
|
||
changed with ChMod.
|
||
|
||
read_only Old fcb-create, new Meaningless.
|
||
Creat, new open (for
|
||
write or read/write)
|
||
will fail.
|
||
|
||
archive Set when file is Meaningless.
|
||
written. Set/reset via
|
||
ChMod.
|
||
|
||
hidden/ Prevents file from Prevents directory
|
||
system being found in search entry from being
|
||
first/search next. found. ChDir to
|
||
New open will fail. directory will still
|
||
work.
|
||
|
||
|
||
Name: * ChDir - Change the current directory
|
||
|
||
Assembler usage:
|
||
LDS DX, name
|
||
MOV AH, ChDir
|
||
INT 21h
|
||
|
||
Description:
|
||
ChDir is given the ASCIZ name of the directory
|
||
which is to become the current directory. If any
|
||
member of the specified pathname does not exist, then
|
||
the current directory is unchanged. Otherwise, the
|
||
current directory is set to the string.
|
||
|
||
Error returns:
|
||
AX = error_path_not_found
|
||
The path specified in DS:DX either indicated a
|
||
file or the path was invalid.
|
||
|
||
|
||
Name: * ChMod - change write protection
|
||
|
||
Assembler usage:
|
||
LDS DX, name
|
||
MOV CX, attribute
|
||
MOV AL, func
|
||
MOV AH, ChMod
|
||
INT 21h
|
||
|
||
Description:
|
||
Given an ASCIZ name, ChMod will set/get the
|
||
attributes of the file to those given in CX.
|
||
|
||
A function code is passed in AL:
|
||
|
||
AL Function
|
||
-- --------
|
||
0 Return the attributes of the file in CX
|
||
1 Set the attributes of the file to those in CX
|
||
|
||
Error returns:
|
||
AX = error_path_not_found
|
||
The path specified was invalid.
|
||
= error_access_denied
|
||
The attributes specified in CX contained one
|
||
that could not be changed (directory, volume
|
||
ID).
|
||
= error_invalid_function
|
||
The function passed in AL was not in the range
|
||
0:1.
|
||
|
||
|
||
Name: * Close - close a file handle
|
||
|
||
Assembler usage:
|
||
MOV BX, handle
|
||
MOV AH, Close
|
||
INT 21h
|
||
|
||
Description:
|
||
In BX is passed a file handle (like that returned
|
||
by Open, Creat or Dup); the Close call will close the
|
||
associated file. Internal buffers are flushed.
|
||
|
||
Error return:
|
||
AX = error_invalid_handle
|
||
The handle passed in BX was not currently
|
||
open.
|
||
|
||
|
||
Name: * Creat - create a file
|
||
|
||
Assembler usage:
|
||
LDS DX, name
|
||
MOV AH, Creat
|
||
MOV CX, attribute
|
||
INT 21h
|
||
; AX now has the handle
|
||
|
||
Description:
|
||
Creat creates a new file or truncates an old file
|
||
to zero length in preparation for writing. If the
|
||
file did not exist, then the file is created in the
|
||
appropriate directory and the file is given the
|
||
read/write protection code of access.
|
||
|
||
CX contains the default attributes to be set for
|
||
the file. Currently, the read-only bit must be off.
|
||
|
||
Error returns:
|
||
AX = error_access_denied
|
||
The attributes specified in CX contained one
|
||
that could not be created (directory, volume
|
||
ID), a file already existed with a more
|
||
inclusive set of attributes, or a directory
|
||
existed with the same name.
|
||
= error_path_not_found
|
||
The path specified was invalid.
|
||
= error_too_many_open_files
|
||
The file was created with the specified
|
||
attributes, but there were no free handles
|
||
available for the process or that the internal
|
||
system tables were full.
|
||
|
||
|
||
Name: * Dup - duplicate a file handle
|
||
|
||
Assembler usage:
|
||
MOV BX, fh
|
||
MOV AH, Dup
|
||
INT 21h
|
||
; AX has the returned handle
|
||
|
||
Description:
|
||
Dup takes an already opened file handle and
|
||
returns a new handle that refers to the same file at
|
||
the same position.
|
||
|
||
Error returns:
|
||
AX = error_invalid_handle
|
||
The handle passed in BX was not currently
|
||
open.
|
||
= error_too_many_open_files
|
||
There were no free handles available in the
|
||
current process or the internal system tables
|
||
were full.
|
||
|
||
|
||
Name: * Dup2 - force a duplicate of a handle
|
||
|
||
Assembler usage:
|
||
MOV BX, fh
|
||
MOV CX, newfh
|
||
MOV AH, Dup2
|
||
INT 21h
|
||
|
||
Description:
|
||
Dup2 will cause newfh to refer to the same stream
|
||
as fh. If there was an open file on newfh, then it is
|
||
closed first.
|
||
|
||
Error returns:
|
||
AX = error_invalid_handle
|
||
The handle passed in BX was not currently
|
||
open.
|
||
|
||
|
||
Name: * Exec - load / execute a program
|
||
|
||
Assembler usage:
|
||
LDS DX, name
|
||
LES BX, blk
|
||
MOV AH, Exec
|
||
MOV AL, func
|
||
INT 21h
|
||
|
||
Description:
|
||
This call allows a program to load another program
|
||
into memory and (default) begin execution of it.
|
||
DS:DX points to the ASCIZ name of the file to be
|
||
loaded. ES:BX points to a parameter block for the
|
||
load.
|
||
|
||
A function code is passed in AL:
|
||
|
||
AL Function
|
||
-- --------
|
||
0 Load and execute the program. A program header is
|
||
established for the program and the terminate and
|
||
^C addresses are set to the instruction after the
|
||
EXEC system call.
|
||
|
||
NOTE: When control is returned, via a ^C or
|
||
terminate, from the program being EXECed ALL
|
||
registers are altered including the stack.
|
||
This is because control is returned from the
|
||
EXECed program, not the system. To regain
|
||
your stack, store an SS:SP value in a data
|
||
location reachable from your CS.
|
||
|
||
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|
||
| C A V E A T P R O G R A M M E R |
|
||
| |
|
||
1 Load, create the program header but do not begin
|
||
execution. The CS:IP/SS:SP of the program are
|
||
returned in the area provided by the user.
|
||
| |
|
||
| C A V E A T P R O G R A M M E R |
|
||
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|
||
|
||
3 Load, do not create the program header, and do not
|
||
begin execution. This is useful in loading
|
||
program overlays.
|
||
|
||
For each value of AL, the block has the following
|
||
format:
|
||
|
||
AL = 0 -> load/execute program
|
||
|
||
+---------------------------+
|
||
| WORD segment address of |
|
||
| environment. |
|
||
+---------------------------+
|
||
| DWORD pointer to command |
|
||
| line at 80h |
|
||
+---------------------------+
|
||
| DWORD pointer to default |
|
||
| FCB to be passed at 5Ch |
|
||
+---------------------------+
|
||
| DWORD pointer to default |
|
||
| FCB to be passed at 6Ch |
|
||
+---------------------------+
|
||
|
||
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|
||
| C A V E A T P R O G R A M M E R |
|
||
| |
|
||
AL = 1 -> load program
|
||
|
||
+---------------------------+
|
||
| WORD segment address of |
|
||
| environment. |
|
||
+---------------------------+
|
||
| DWORD pointer to command |
|
||
| line at 80h |
|
||
+---------------------------+
|
||
| DWORD pointer to default |
|
||
| FCB to be passed at 5Ch |
|
||
+---------------------------+
|
||
| DWORD pointer to default |
|
||
| FCB to be passed at 6Ch |
|
||
+---------------------------+
|
||
| DWORD returned value of |
|
||
| SS:SP |
|
||
+---------------------------+
|
||
| DWORD returned value of |
|
||
| CS:IP |
|
||
+---------------------------+
|
||
| |
|
||
| C A V E A T P R O G R A M M E R |
|
||
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|
||
|
||
AL = 3 -> load overlay
|
||
|
||
+---------------------------+
|
||
| WORD segment address where|
|
||
| file will be loaded. |
|
||
+---------------------------+
|
||
| WORD relocation factor to |
|
||
| be applied to the image. |
|
||
+---------------------------+
|
||
|
||
Note that all open files of a process are
|
||
duplicated in the child process after an Exec. This
|
||
is extremely powerful; the parent process has control
|
||
over the meanings of stdin, stdout, stderr, stdaux and
|
||
stdprn. The parent could, for example, write a series
|
||
of records to a file, open the file as standard input,
|
||
open a listing file as standard output and then Exec a
|
||
sort program that takes its input from stdin and
|
||
writes to stdout.
|
||
|
||
Also inherited (or passed from the parent) is an
|
||
'environment'. This is a block of text strings (less
|
||
than 32K bytes total) that convey various
|
||
configurations parameters. The format of the
|
||
environment is as follows:
|
||
|
||
(paragraph boundary)
|
||
+---------------------------+
|
||
| BYTE asciz string 1 |
|
||
+---------------------------+
|
||
| BYTE asciz string 2 |
|
||
+---------------------------+
|
||
| ... |
|
||
+---------------------------+
|
||
| BYTE asciz string n |
|
||
+---------------------------+
|
||
| BYTE of zero |
|
||
+---------------------------+
|
||
|
||
Typically the environment strings have the form:
|
||
|
||
parameter=value
|
||
|
||
for example, COMMAND.COM always passes its execution
|
||
search path as:
|
||
|
||
PATH=A:/BIN;B:/BASIC/LIB
|
||
|
||
A zero value of the environment address will cause the
|
||
child process to inherit the parent's environment
|
||
unchanged.
|
||
|
||
Note that on a successful return from EXEC, all
|
||
registers, except for CS:IP, are changed.
|
||
|
||
Error return:
|
||
AX = error_invalid_function
|
||
The function passed in AL was not 0, 1 or 3.
|
||
= error_bad_environment
|
||
The environment was larger than 32Kb.
|
||
= error_bad_format
|
||
The file pointed to by DS:DX was an EXE format
|
||
file and contained information that was
|
||
internally inconsistent.
|
||
= error_not_enough_memory
|
||
There was not enough memory for the process to
|
||
be created.
|
||
= error_file_not_found
|
||
The path specified was invalid or not found.
|
||
|
||
|
||
Name: * Exit - terminate a process
|
||
|
||
Assembler usage:
|
||
MOV AL, code
|
||
MOV AH, Exit
|
||
INT 21h
|
||
|
||
Description:
|
||
Exit will terminate the current process,
|
||
transferring control to the invoking process. In
|
||
addition, a return code may be sent. All files open
|
||
at the time are closed.
|
||
|
||
Error returns:
|
||
None.
|
||
|
||
|
||
Name: * Ioctl - I/O control for devices
|
||
|
||
Assembler usage:
|
||
MOV BX, Handle
|
||
|
||
(or MOV BL, drive for calls AL=4,5
|
||
0=default,A=1...)
|
||
|
||
MOV DX, Data
|
||
|
||
(or LDS DX, buf and
|
||
MOV CX, count for calls AL=2,3,4,5)
|
||
|
||
MOV AH, Ioctl
|
||
MOV AL, func
|
||
INT 21h
|
||
; For calls AL=2,3,4,5 AX is the number of bytes
|
||
; transferred (same as READ and WRITE).
|
||
; For calls AL=6,7 AL is status returned, AL=0 if
|
||
; status is not ready, AL=0FFH otherwise.
|
||
|
||
Description:
|
||
Set or Get device information associated with open
|
||
Handle, or send/receive control string to device
|
||
Handle or device.
|
||
|
||
The following values are allowed for func:
|
||
|
||
Request Function
|
||
------ --------
|
||
0 Get device information (returned in DX)
|
||
1 Set device information (as determined by DX)
|
||
2 Read CX number of bytes into DS:DX from device
|
||
control channel.
|
||
3 Write CX number of bytes from DS:DX to device
|
||
control channel.
|
||
4 Same as 2 only drive number in BL
|
||
0=default,A=1,B=2,...
|
||
5 Same as 3 only drive number in BL
|
||
0=default,A=1,B=2,...
|
||
6 Get input status
|
||
7 Get output status
|
||
|
||
Ioctl can be used to get information about device
|
||
channels. It is ok to make Ioctl calls on regular
|
||
files but only calls 0,6 and 7 are defined in that
|
||
case (AL=0,6,7), all other calls return an
|
||
error_invalid_function error.
|
||
|
||
CALLS AL=0 and AL=1
|
||
|
||
The bits of DX are defined as follows for calls
|
||
AL=0 and AL=1. Note that the upper byte MUST be zero
|
||
on a set call.
|
||
|
||
|
|
||
15 14 13 12 11 10 9 8|7 6 5 4 3 2 1 0
|
||
+--+--+--+--+--+--+-+-+-+-+-+-+-+-+-+-+
|
||
| R| C| |I|E|R|S|I|I|I|I|
|
||
| e| T| |S|O|A|P|S|S|S|S|
|
||
| s| R| Reserved |D|F|W|E|C|N|C|C|
|
||
| | L| |E| | |C|L|U|O|I|
|
||
| | | |V| | |L|K|L|T|N|
|
||
+--+--+--+--+--+--+-+-+-+-+-+-+-+-+-+-+
|
||
|
|
||
|
||
ISDEV = 1 if this channel is a device
|
||
= 0 if this channel is a disk file (Bits 8-15 =
|
||
0 in this case)
|
||
|
||
If ISDEV = 1
|
||
|
||
EOF = 0 if End Of File on input
|
||
RAW = 1 if this device is in Raw mode
|
||
= 0 if this device is cooked
|
||
ISCLK = 1 if this device is the clock device
|
||
ISNUL = 1 if this device is the null device
|
||
ISCOT = 1 if this device is the console output
|
||
ISCIN = 1 if this device is the console input
|
||
SPECL = 1 if this device is special
|
||
|
||
CTRL = 0 if this device can NOT do control strings
|
||
via calls AL=2 and AL=3.
|
||
CTRL = 1 if this device can process control
|
||
strings via calls AL=2 and AL=3.
|
||
NOTE that this bit cannot be set.
|
||
|
||
If ISDEV = 0
|
||
EOF = 0 if channel has been written
|
||
Bits 0-5 are the block device number for the
|
||
channel (0 = A, 1 = B, ...)
|
||
|
||
Bits 15,8-13,4 are reserved and should not be altered.
|
||
|
||
Calls 2..5:
|
||
These four calls allow arbitrary control strings to be
|
||
sent or received from a device. The Call syntax is
|
||
the same as the READ and WRITE calls, except for 4 and
|
||
5 which take a drive number in BL instead of a handle
|
||
in BX.
|
||
|
||
An error_invalid_function error is returned if the
|
||
CTRL bit (see above) is 0.
|
||
|
||
An error_access_denied is returned by calls AL=4,5 if
|
||
the drive number is invalid.
|
||
|
||
Calls 6,7:
|
||
These two calls allow the user to check if a file
|
||
handle is ready for input or output. Status of
|
||
handles open to a device is the intended use of these
|
||
calls, but status of a handle open to a disk file is
|
||
OK and is defined as follows:
|
||
|
||
Input:
|
||
Always ready (AL=FF) until EOF reached, then
|
||
always not ready (AL=0) unless current
|
||
position changed via LSEEK.
|
||
Output:
|
||
Always ready (even if disk full).
|
||
|
||
IMPORTANT NOTE:
|
||
The status is defined at the time the system is
|
||
CALLED. On future versions, by the time control is
|
||
returned to the user from the system, the status
|
||
returned may NOT correctly reflect the true current
|
||
state of the device or file.
|
||
|
||
Error returns:
|
||
AX = error_invalid_handle
|
||
The handle passed in BX was not currently
|
||
open.
|
||
= error_invalid_function
|
||
The function passed in AL was not in the range
|
||
0:7.
|
||
= error_invalid_data
|
||
= error_access_denied (calls AL=4..7)
|
||
|
||
|
||
Name: * LSeek - move file read/write pointer
|
||
|
||
Assembler usage:
|
||
MOV DX, offsetlow
|
||
MOV CX, offsethigh
|
||
MOV AL, method
|
||
MOV BX, handle
|
||
MOV AH, LSeek
|
||
INT 21h
|
||
; DX:AX has the new location of the pointer
|
||
|
||
Description:
|
||
LSeek moves the read/write pointer according to
|
||
method:
|
||
|
||
Method Function
|
||
------ --------
|
||
0 The pointer is moved to offset bytes from the
|
||
beginning of the file.
|
||
1 The pointer is moved to the current location
|
||
plus offset.
|
||
2 The pointer is moved to the end of file plus
|
||
offset.
|
||
|
||
Offset should be regarded as a 32-bit integer with
|
||
CX occupying the most significant 16 bits.
|
||
|
||
Error returns:
|
||
AX = error_invalid_handle
|
||
The handle passed in BX was not currently
|
||
open.
|
||
= error_invalid_function
|
||
The function passed in AL was not in the range
|
||
0:2.
|
||
|
||
|
||
Name: * MkDir - Create a directory entry
|
||
|
||
Assembler usage:
|
||
LDS DX, name
|
||
MOV AH, MkDir
|
||
INT 21h
|
||
|
||
Description:
|
||
Given a pointer to an ASCIZ name, create a new
|
||
directory entry at the end.
|
||
|
||
Error returns:
|
||
AX = error_path_not_found
|
||
The path specified was invalid or not found.
|
||
= error_access_denied
|
||
The directory could not be created (no room in
|
||
parent directory), the directory/file already
|
||
existed or a device name was specified.
|
||
|
||
|
||
Name: * Open - access a file
|
||
|
||
Assembler usage:
|
||
LDS DX, name
|
||
MOV AH, Open
|
||
MOV AL, access
|
||
INT 21h
|
||
; AX has error or file handle
|
||
; If successful open
|
||
|
||
Description:
|
||
Open associates a 16-bit file handle with a file.
|
||
|
||
The following values are allowed for access:
|
||
|
||
ACCESS Function
|
||
------ --------
|
||
0 file is opened for reading
|
||
1 file is opened for writing
|
||
2 file is opened for both reading and writing.
|
||
|
||
DS:DX point to an ASCIZ name of the file to be
|
||
opened.
|
||
|
||
The read/write pointer is set at the first byte of
|
||
the file and the record size of the file is 1 byte.
|
||
The returned file handle must be used for subsequent
|
||
I/O to the file.
|
||
|
||
The DOS, on initialization, will have a maximum
|
||
number of files. See the configuration file document
|
||
for information on changing this default.
|
||
|
||
Error returns:
|
||
AX = error_invalid_access
|
||
The access specified in AL was not in the
|
||
range 0:2.
|
||
= error_file_not_found
|
||
The path specified was invalid or not found.
|
||
= error_access_denied
|
||
The user attempted to open a directory or
|
||
volume-id, or open a read-only file for
|
||
writing.
|
||
= error_too_many_open_files
|
||
There were no free handles available in the
|
||
current process or the internal system tables
|
||
were full.
|
||
|
||
|
||
Name: * Read - Do file/device I/O
|
||
|
||
Assembler usage:
|
||
LDS DX, buf
|
||
MOV CX, count
|
||
MOV BX, handle
|
||
MOV AH, Read
|
||
INT 21h
|
||
; AX has number of bytes read
|
||
|
||
Description:
|
||
Read transfers count bytes from a file into a
|
||
buffer location. It is not guaranteed that all count
|
||
bytes will be read; for example, reading from the
|
||
keyboard will read at most one line of text. If the
|
||
returned value is zero, then the program has tried to
|
||
read from the end of file.
|
||
|
||
All I/O is done using normalized pointers; no
|
||
segment wraparound will occur.
|
||
|
||
Error returns:
|
||
AX = error_invalid_handle
|
||
The handle passed in BX was not currently
|
||
open.
|
||
= error_access_denied
|
||
The handle passed in BX was opened in a mode
|
||
that did not allow reading.
|
||
|
||
|
||
Name: * RmDir - Remove a directory entry
|
||
|
||
Assembler usage:
|
||
LDS DX, name
|
||
MOV AH, RmDir
|
||
INT 21h
|
||
|
||
Description:
|
||
RmDir is given an asciz name of a directory. That
|
||
directory is removed from its parent
|
||
|
||
Error returns:
|
||
AX = error_path_not_found
|
||
The path specified was invalid or not found.
|
||
= error_access_denied
|
||
The path specified was not empty, not a
|
||
directory, the root directory or contained
|
||
invalid information.
|
||
= error_current_directory
|
||
The path specified was the current directory
|
||
on a drive.
|
||
|
||
|
||
Name: * Unlink - delete a directory entry
|
||
|
||
Assembler usage:
|
||
LDS DX, name
|
||
MOV AH, Unlink
|
||
INT 21h
|
||
|
||
Description:
|
||
Unlink removes a directory entry associated with a
|
||
filename. If the file is currently open on another
|
||
handle, then no removal will take place.
|
||
|
||
Error returns:
|
||
AX = error_file_not_found
|
||
The path specified was invalid or not found.
|
||
= error_access_denied
|
||
The path specified was a directory or
|
||
read-only.
|
||
|
||
|
||
Name: * Wait - retrieve the return code of a child
|
||
|
||
Assembler usage:
|
||
MOV AH, Wait
|
||
INT 21h
|
||
; AX has the exit code
|
||
|
||
Description:
|
||
Wait will return the Exit code specified by a
|
||
child process. It will return this Exit code only
|
||
once. The low byte of this code is that sent by the
|
||
Exit routine. The high byte is one of the following:
|
||
|
||
0 - terminate/abort
|
||
1 - ^C
|
||
2 - Hard error
|
||
3 - Terminate and stay resident
|
||
|
||
Error returns:
|
||
None.
|
||
|
||
|
||
Name: * Write - write to a file
|
||
|
||
Assembler usage:
|
||
LDS DX, buf
|
||
MOV CX, count
|
||
MOV BX, handle
|
||
MOV AH, Write
|
||
INT 21h
|
||
; AX has number of bytes written
|
||
|
||
Description:
|
||
Write transfers count bytes from a buffer into
|
||
a file. It should be regarded as an error if the
|
||
number of bytes written is not the same as the number
|
||
requested.
|
||
|
||
It is important to note that the write system
|
||
call with a count of zero (CX = 0) will truncate
|
||
the file at the current position.
|
||
|
||
All I/O is done using normalized pointers; no
|
||
segment wraparound will occur.
|
||
|
||
Error Returns:
|
||
AX = error_invalid_handle
|
||
The handle passed in BX was not currently
|
||
open.
|
||
= error_access_denied
|
||
The handle was not opened in a mode that
|
||
allowed writing.
|
||
|
||
|
||
The following XENIX convention is followed for the new 2.0
|
||
system calls:
|
||
|
||
o If no error occurred, then the carry flag will be
|
||
reset and register AX will contain the appropriate
|
||
information.
|
||
|
||
o If an error occurred, then the carry flag will be
|
||
set and register AX will contain the error code.
|
||
|
||
The following code sample illustrates the recommended method
|
||
of detecting these errors:
|
||
|
||
...
|
||
MOV errno,0
|
||
INT 21h
|
||
JNC continue
|
||
MOV errno,AX
|
||
continue:
|
||
...
|
||
|
||
The word variable errno will now have the correct error code
|
||
for that system call.
|
||
|
||
The current equates for the error codes are:
|
||
|
||
no_error_occurred EQU 0
|
||
|
||
error_invalid_function EQU 1
|
||
error_file_not_found EQU 2
|
||
error_path_not_found EQU 3
|
||
error_too_many_open_files EQU 4
|
||
error_access_denied EQU 5
|
||
error_invalid_handle EQU 6
|
||
error_arena_trashed EQU 7
|
||
error_not_enough_memory EQU 8
|
||
error_invalid_block EQU 9
|
||
error_bad_environment EQU 10
|
||
error_bad_format EQU 11
|
||
error_invalid_access EQU 12
|
||
error_invalid_data EQU 13
|
||
error_invalid_drive EQU 15
|
||
error_current_directory EQU 16
|
||
error_not_same_device EQU 17
|
||
error_no_more_files EQU 18
|
||
|
||
|
||
System call assignments:
|
||
|
||
ABORT EQU 0 ; 0 0
|
||
STD_CON_INPUT EQU 1 ; 1 1
|
||
STD_CON_OUTPUT EQU 2 ; 2 2
|
||
STD_AUX_INPUT EQU 3 ; 3 3
|
||
STD_AUX_OUTPUT EQU 4 ; 4 4
|
||
STD_PRINTER_OUTPUT EQU 5 ; 5 5
|
||
RAW_CON_IO EQU 6 ; 6 6
|
||
RAW_CON_INPUT EQU 7 ; 7 7
|
||
STD_CON_INPUT_NO_ECHO EQU 8 ; 8 8
|
||
STD_CON_STRING_OUTPUT EQU 9 ; 9 9
|
||
STD_CON_STRING_INPUT EQU 10 ; 10 A
|
||
STD_CON_INPUT_STATUS EQU 11 ; 11 B
|
||
STD_CON_INPUT_FLUSH EQU 12 ; 12 C
|
||
DISK_RESET EQU 13 ; 13 D
|
||
SET_DEFAULT_DRIVE EQU 14 ; 14 E
|
||
FCB_OPEN EQU 15 ; 15 F
|
||
FCB_CLOSE EQU 16 ; 16 10
|
||
DIR_SEARCH_FIRST EQU 17 ; 17 11
|
||
DIR_SEARCH_NEXT EQU 18 ; 18 12
|
||
FCB_DELETE EQU 19 ; 19 13
|
||
FCB_SEQ_READ EQU 20 ; 20 14
|
||
FCB_SEQ_WRITE EQU 21 ; 21 15
|
||
FCB_CREATE EQU 22 ; 22 16
|
||
FCB_RENAME EQU 23 ; 23 17
|
||
GET_DEFAULT_DRIVE EQU 25 ; 25 19
|
||
SET_DMA EQU 26 ; 26 1A
|
||
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|
||
| C A V E A T P R O G R A M M E R |
|
||
| |
|
||
GET_DEFAULT_DPB EQU 31 ; 31 1F
|
||
| |
|
||
| C A V E A T P R O G R A M M E R |
|
||
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|
||
FCB_RANDOM_READ EQU 33 ; 33 21
|
||
FCB_RANDOM_WRITE EQU 34 ; 34 22
|
||
GET_FCB_FILE_LENGTH EQU 35 ; 35 23
|
||
GET_FCB_POSITION EQU 36 ; 36 24
|
||
SET_INTERRUPT_VECTOR EQU 37 ; 37 25
|
||
CREATE_PROCESS_DATA_BLOCK EQU 38 ; 38 26
|
||
FCB_RANDOM_READ_BLOCK EQU 39 ; 39 27
|
||
FCB_RANDOM_WRITE_BLOCK EQU 40 ; 40 28
|
||
PARSE_FILE_DESCRIPTOR EQU 41 ; 41 29
|
||
GET_DATE EQU 42 ; 42 2A
|
||
SET_DATE EQU 43 ; 43 2B
|
||
GET_TIME EQU 44 ; 44 2C
|
||
SET_TIME EQU 45 ; 45 2D
|
||
SET_VERIFY_ON_WRITE EQU 46 ; 46 2E
|
||
; Extended functionality group
|
||
GET_DMA EQU 47 ; 47 2F
|
||
GET_VERSION EQU 48 ; 48 30
|
||
KEEP_PROCESS EQU 49 ; 49 31
|
||
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|
||
| C A V E A T P R O G R A M M E R |
|
||
| |
|
||
GET_DPB EQU 50 ; 50 32
|
||
| |
|
||
| C A V E A T P R O G R A M M E R |
|
||
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|
||
SET_CTRL_C_TRAPPING EQU 51 ; 51 33
|
||
GET_INDOS_FLAG EQU 52 ; 52 34
|
||
GET_INTERRUPT_VECTOR EQU 53 ; 53 35
|
||
GET_DRIVE_FREESPACE EQU 54 ; 54 36
|
||
CHAR_OPER EQU 55 ; 55 37
|
||
INTERNATIONAL EQU 56 ; 56 38
|
||
; XENIX CALLS
|
||
; Directory Group
|
||
MKDIR EQU 57 ; 57 39
|
||
RMDIR EQU 58 ; 58 3A
|
||
CHDIR EQU 59 ; 59 3B
|
||
; File Group
|
||
CREAT EQU 60 ; 60 3C
|
||
OPEN EQU 61 ; 61 3D
|
||
CLOSE EQU 62 ; 62 3E
|
||
READ EQU 63 ; 63 3F
|
||
WRITE EQU 64 ; 64 40
|
||
UNLINK EQU 65 ; 65 41
|
||
LSEEK EQU 66 ; 66 42
|
||
CHMOD EQU 67 ; 67 43
|
||
IOCTL EQU 68 ; 68 44
|
||
XDUP EQU 69 ; 69 45
|
||
XDUP2 EQU 70 ; 70 46
|
||
CURRENT_DIR EQU 71 ; 71 47
|
||
; Memory Group
|
||
ALLOC EQU 72 ; 72 48
|
||
DEALLOC EQU 73 ; 73 49
|
||
SETBLOCK EQU 74 ; 74 4A
|
||
; Process Group
|
||
EXEC EQU 75 ; 75 4B
|
||
EXIT EQU 76 ; 76 4C
|
||
WAIT EQU 77 ; 77 4D
|
||
FIND_FIRST EQU 78 ; 78 4E
|
||
; Special Group
|
||
FIND_NEXT EQU 79 ; 79 4F
|
||
; SPECIAL SYSTEM GROUP
|
||
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|
||
| C A V E A T P R O G R A M M E R |
|
||
| |
|
||
SET_CURRENT_PDB EQU 80 ; 80 50
|
||
GET_CURRENT_PDB EQU 81 ; 81 51
|
||
GET_IN_VARS EQU 82 ; 82 52
|
||
SETDPB EQU 83 ; 83 53
|
||
| |
|
||
| C A V E A T P R O G R A M M E R |
|
||
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|
||
GET_VERIFY_ON_WRITE EQU 84 ; 84 54
|
||
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|
||
| C A V E A T P R O G R A M M E R |
|
||
| |
|
||
DUP_PDB EQU 85 ; 85 55
|
||
| |
|
||
| C A V E A T P R O G R A M M E R |
|
||
+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
|
||
RENAME EQU 86 ; 86 56
|
||
FILE_TIMES EQU 87 ; 87 57
|
||
|