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| author | Lars-Dominik Braun <lars@6xq.net> | 2019-02-11 11:49:19 +0100 |
|---|---|---|
| committer | Lars-Dominik Braun <lars@6xq.net> | 2019-02-11 11:49:39 +0100 |
| commit | 98cab31fc3659e33aef260efca55bf9f1753164c (patch) | |
| tree | f1affa84049ef9b268e6c4f521f000478b0f3a8e /system/dos/1986/doc | |
| parent | 71e2b36ccd05ea678e62e32ee6245df2b8d6ac17 (diff) | |
| download | eumel-src-98cab31fc3659e33aef260efca55bf9f1753164c.tar.gz eumel-src-98cab31fc3659e33aef260efca55bf9f1753164c.tar.bz2 eumel-src-98cab31fc3659e33aef260efca55bf9f1753164c.zip | |
Add source files from Michael
Diffstat (limited to 'system/dos/1986/doc')
| -rw-r--r-- | system/dos/1986/doc/DSKDOS.ELA | 967 |
1 files changed, 967 insertions, 0 deletions
diff --git a/system/dos/1986/doc/DSKDOS.ELA b/system/dos/1986/doc/DSKDOS.ELA new file mode 100644 index 0000000..69bc714 --- /dev/null +++ b/system/dos/1986/doc/DSKDOS.ELA @@ -0,0 +1,967 @@ +#type ("17.klein")#
+prefix of extended fcb:
+
+ offset size name
+ -7 1 flag byte 255
+ -6 5 reserved
+ -1 1 attribute byte 2=hidden file, 4=system file
+
+normal fcb format:
+
+ offset size name
+ 0 1 drive number 0=default (for open), 1=A, 2=B
+ 1 8 filename 8 chars, left aligned and padded
+ (if necessary) with blanks
+ 9 3 extension 3 chars, left aligned and padded
+ (if necessary) with blanks
+ 12 2 current block pointer to the block of 128 records
+ containing the current record
+ (0 after open)
+ 14 2 record size logical record size in bytes
+ (128 after open, changed eventually)
+ 16 4 file size file size in bytes (1. byte low)
+ 20 2 date of last write 20:mmmddddd 21:yyyyyyym
+ 22 2 time of last write 22:mmmsssss 23:hhhhhmmm
+ 24 8 reserved
+ 32 1 current record pointer to one of the 128 records in
+ the block (not initialized by open)
+ must be set before sequential read/write
+ 33 4 relative record pointer to selected record
+ (counting from the beginning of file by 0)
+ not initialized by open
+ must be set before sequential read/write
+ record size less than
+ 64 bytes: both words used
+ else only first 3 bytes
+
+fields of directory entry:
+
+ offset size name
+ 0 8 filename 8 chars, left aligned and padded
+ (if necessary) with blanks
+ special use of first byte:
+ 0 : end of allocated directory
+ 229: free directory entry
+ 8 3 extension 3 chars, left aligned and padded
+ (if necessary) with blanks
+ 11 1 attributes 1: read only file
+ 2: hidden file
+ 4: system file
+ 8: entry is the volume's id
+ 16: entry is subdirectory's name
+ 32: archive bit (set, when written to)
+ 12 10 reserved
+ 22 2 time of last write 22:mmmsssss 23:hhhhhmmm
+ 24 2 date of last write 24:mmmddddd 25:yyyyyyym
+ 26 2 reserved
+ 28 4 file size file size in bytes (1. byte low)
+
+directory structure:
+
+ - the root directory has a fixed number of entries
+ - entries that represent a subdirectory have a special attribute in their
+ entry set
+ - the subdirectories are themselves files which records are of the same type
+ as those in the root directory
+ - the number of entries in subdirectories are not limited
+ - the length of a path to a subdirectory is not limited
+
+application of the directory entry fields on subdirectory entries:
+
+ volume id : present at root, only one entry has this attribute
+ directory : the directory entry represents itself an directory
+ read only : meaningless
+ archive : meaningless
+ hidden/system: prevents directories from beeing found, function $3B
+ will still work
+
+ms-dos interrupts:
+
+ $20 : program terminate
+ call:
+ CS: segment address
+ terminates process, returns control to parent process,
+ file handles are closed, disk cache cleaned, file buffers flushed
+ programm terminate, alt-c and critical error addresses are restored
+ new programs should use function $4C
+ $21 : function request
+ call:
+ AH: function number
+ other registers dependent on function
+ $22 to $24 :
+ address locations for msdos use
+ can be changed by function $25
+ $22 : terminate address
+ $23 : alt-c exit address
+ address of an alt-c routine
+ $24 : fatal error abort address
+ address of the error handler
+ BP:SI can contain further information
+ not called if error occurs during absolute disk operations (int $25,$26)
+ $25 : absolute disk read
+ call:
+ AL: drive number
+ DS:BX: disk transfer address
+ CX: number of sectors
+ DX: beginning relative sector
+ return:
+ CF: 0=successful
+ 1=unsuccessful
+ AL: error code if unsuccessful
+ $26 : absolute disk write
+ call:
+ AL: drive number
+ DS:BX: disk transfer address
+ CX: number of sectors
+ DX: beginning relative sector
+ return:
+ CF: 0=successful
+ 1=unsuccessful
+ AL: error code if unsuccessful
+ $27 : terminate but stay resident
+ call:
+ CS:DX: first byte following the code
+ new programms should use function $31
+
+ms-dos function requests:
+
+ $00 : terminate program
+ call:
+ AH: $00
+ CS: segment of programm prefix
+ $01 : read keyboard and echo
+ call:
+ AH: $01
+ return:
+ AL: character typed
+ waits for input, echos and returns it
+ alt-c will call interrupt
+ $02 : display character
+ call:
+ AH: $02
+ DL: character to be displayed
+ alt-c will call interrupt
+ $03 : auxiliary input
+ call:
+ AH: $03
+ return:
+ AL: character from auxiliary device
+ waits for input, alt-c will call interrupt
+ $04 : auxiliary output
+ call:
+ AH: $04
+ DL: character to output
+ alt-c will call interrupt
+ $05 : print character
+ call:
+ AH: $05
+ DL: character for printer
+ alt-c will call interrupt
+ $06 : direct console i/o
+ call:
+ AH: $06
+ DL: $FF: check for keyboard input
+ otherwise: display DL on screen
+ return:
+ ZF: 0=no char available
+ 1=char was read
+ AL: char if read
+ $07 : direct konsole input
+ call:
+ AH: $07
+ return:
+ AL: character from keyboard
+ waits for character
+ $08 : read keyboard
+ call:
+ AH: $08
+ return:
+ AL: character from keyboard
+ waits for character, alt-c will call interrupt
+ $09 : display string
+ call:
+ AH: $09
+ DS:DX: string, ending with '$'
+ $0A : buffered keyboard input
+ call:
+ AH: $0A
+ DS:DX: input buffer
+ byte 1: maximum number of chars in buffer (with CR)
+ 2: actual number of chars in buffer (set by function)
+ 3-n: must be at least as long as the max
+ waits for chars, allows editing, ignores overflow,
+ alt-c will call interrupt
+ $0B : check keyboard status
+ call:
+ AH: $0B
+ return:
+ AL: 0=no chars in type-ahead buffer
+ 255=chars available
+ $0C : flush buffer and read keyboard
+ call:
+ AH: $0C
+ AL: $01,$06,$07,$08 or $0A: corresponding function is called
+ other values: no further processing
+ return:
+ AL: 0=type ahead buffer was flushed, no processing performed
+ $0D : disk reset
+ call:
+ AH: $0D
+ all disk buffers are flushed, no directory updates performed
+ $0E : select disk
+ call:
+ AH: $0E
+ DL: drive number, 1=A, 2=B, ..
+ return:
+ AL: number of logical drives
+ $0F : open file
+ call:
+ AH: $0F
+ DS:DX: unopened fcb
+ return:
+ AL: 0=directory entry found
+ if drive code was 0, it is set to the default
+ current block is set to 0
+ record size is set to 128
+ file size, time and date of last modification are set
+ from directory
+ the default record size must be set, if not 128
+ before performing a sequential (random) operation,
+ current record (relative record) field must be set
+ 255=no directory entry found
+
+ $10 : close file
+ call:
+ AH: $10
+ DS:DX: opened fcb
+ return:
+ AL: 0=directory entry found
+ 255=no directory entry found
+ $11 : search for first entry
+ call:
+ AH: $11
+ DS:DX: unopened fcb
+ return:
+ 0=directory entry found
+ fcb (normal or extended) is created
+ at the disk transfer address
+ 255=no directory entry found
+ to search for hidden or system files, the fcb must be extended
+ see notes on search attributes
+ $12 : search for next entry
+ call:
+ AH: $12
+ DS:DX: unopened fcb
+ return:
+ AL: 0=directory entry found
+ fcb (normal or extended) is created
+ at the disk transfer address
+ 255=no directory entry found
+ the fcb must be one used previously in a call to $11
+ $13 : delete file
+ call:
+ AH: $13
+ DS:DX: unopened fcb
+ return:
+ AL: 0=directory entry found
+ 255=no directory entry found
+ deletes all files with matching names
+ $14 : sequential read
+ call:
+ AH: $14
+ DS:DX: opened fcb
+ return:
+ AL: 0=read completed successfully
+ 1=eof, no data in the record
+ 2=dta too small, not enough space to read without exceeding
+ the segment boundaries, read cancelled
+ 3=eof, partial record was read and padded to the record
+ length with zeros
+ the record pointed to by the current block and current record
+ is loaded to the disk transfer address and the fields are incremented
+ $15 : sequential write
+ call:
+ AH: $15
+ DS:DX: opened fcb
+ return:
+ AL: 0=write completed successfully
+ 1=disk full, write canceled
+ 2=dta too small to write one record without exceeding the
+ segment boundaries, write canceled
+ the record pointed to by the current block and current record
+ are written from the disk transfer address and the fields are incremented
+ $16 : create file
+ call:
+ AH: $16
+ DS:DX: unopened fcb
+ return:
+ AL: 0=empty directory entry found
+ 255=no empty entry available and file didn't exist before
+ if the file does already exist, it is made a zero length file
+ else it is created if an empty entry is found
+ $17 : rename file
+ call:
+ AH: $17
+ DS:DX: modified fcb
+ return:
+ AL: 0=directory entry found
+ 255=no directory entry found or destination already exists
+ the fcb must contain the search file name and another file name
+ at offset $11
+ $19 : current disk
+ call:
+ AH: $19
+ return:
+ AL: selected drive (0=A, 1=B, .. )
+ $1A : set disk transfer address
+ call:
+ AH: $1A
+ DS:DX: disk transfer address
+ default is $80 in the psp
+ $21 : random read
+ call:
+ AH: $21
+ DS:DX: opened fcb
+ return:
+ 0=read completed successfully
+ 1=eof, no data read
+ 2=dta too small, read canceled
+ 3=eof, partial record, padded with zeros
+ the current block and current record fields are set to match the
+ relative record field, then the record is loaded
+ $22 : random write
+ call:
+ AH: $22
+ DS:DX: opened fcb
+ return:
+ AL: 0=write completed successfully
+ 1=disk full
+ 2=dta too small, read canceled
+ $23 : file size
+ call:
+ AH: $23
+ DS:DX: unopened fcb
+ return:
+ AL: 0=directory entry found
+ the relative record field is set to the number
+ of records in the file
+ 255=no directory entry found
+ the record size field must be set
+ $24 : set relative record
+ call:
+ AH: $24
+ DS:DX: opened fcb
+ the relative record field is set to the same record as the current block
+ an the current record field
+ $25 : set vector
+ call:
+ AH: $25
+ AL: interrupt number
+ DS:DX: interrupt handling routine
+ $27 : random block read
+ call:
+ AH: $27
+ DS:DX: opened fcb
+ CX: number of blocks to read
+ return:
+ AL: 0=read completed successfully
+ 1=eof, no data read
+ 2=end of segment, read canceled
+ 3=eof, partial record, padded with zeros
+ CX: number of blocks read
+ the reading starts at the relative record
+ the current block, current record and relative record field are updated
+ $28 : random block write
+ call:
+ AH: $28
+ DS:DX: opened fcb
+ CX: number of records to write
+ 0=set file size
+ the file size field of thedirectory entry is set to the number
+ of records specified by the relative record field
+ return:
+ AL: 0=write completed successfully
+ 1=disk full, no records written
+ 2=end of dta-segment, read canceled
+ CX: number of blocks written
+ the writing starts at the relative record
+ the current block, current record and relative record field are updated
+ $29 : parse file name
+ call:
+ AH: $29
+ AL: controls parsing
+ bit 0: if file separators are encountered
+ (: . ; , = + / " [ ] \ < ] | blank tab)
+ 0: all parsing stops
+ 1: leading separators are ignored
+ bit 1: if the string does not contain a drive letter
+ 0: the fcb drive number is set to 0 (default)
+ 1: the fcb drive number is not changed
+ bit 2: if the string does not contain a filename
+ 0: the fcb filename is set to 8 blanks
+ 1: the fcb filename is not changed
+ bit 3: if the string does not contain an extension
+ 0: the fcb extension is set to three blanks
+ 1: the fcb extension is not changed
+ DS:SI: string to parse
+ filename terminators include all filename separators
+ plus any control character
+ ES:DI: if the string contained a valid filename,
+ it points to an unopened fcb
+ else ES:DI+1 points to a blank
+ return:
+ AL: 0=no wild card characters
+ 1=wild card characters used
+ 255=drive letter invalid
+ DS:SI: first byte past string that was parsed
+ if the filename contains an asterisk,
+ all folowing letters are set to question mark
+ ES:DI: unopened fcb
+ if filename is found, an unopened fcb is created here
+ $2A : get date
+ call:
+ AH: $2A
+ return:
+ CX: year (1980-2099)
+ DH: month (1-12)
+ DL: day (1-31)
+ AL: day of week (0=sun, .., 6=sat)
+ $2B : set date
+ call:
+ AH: $2B
+ CX: year (1980-2099)
+ DH: month (1-12)
+ DL: day (1-31)
+ return:
+ AL: 0=date was valid
+ 255=date was invalid
+ $2C : get time
+ call:
+ AH: $2C
+ return:
+ CH: hour (0-23)
+ CL: minutes (0-59)
+ DH: seconds (0-59)
+ DL: hundredths (0-99)
+ $2D : set time
+ call:
+ AH: $2D
+ CH: hour (0-23)
+ CL: minutes (0-59)
+ DH: seconds (0-59)
+ DL: hundredths (0-99)
+ return:
+ AL: 0=time was valid
+ 255=time was invalid
+ $2E : set/reset verify flag
+ call:
+ AH: $2E
+ AL: 0=do not verify
+ 1=verify
+ $2F : get disk transfer address
+ call:
+ AH: $2F
+ return:
+ ES:BX: points to disk transfer address
+ $30 : get dos version number
+ call:
+ AH: $30
+ return:
+ AL: major version number
+ AH: minor version number
+ $31 : keep process
+ call:
+ AH: $31
+ AL: exit code
+ DX: memory size in paragraphs
+ attemts to set the initial allocation block to a specific size
+ in paragraphs, will not free up other allocation blocks belonging
+ to that process, the exit code is available via function $4D
+ $33 : alt-c check
+ call:
+ AH: $33
+ AL: function
+ 0=request current state
+ 1=set state
+ DL: if setting
+ 0=off
+ 1=on
+ return:
+ AL: 255=al parameter was not in range 0..1
+ DL: if requesting current state
+ 0=off
+ 1=on
+ if check is on, every system call executes the check,
+ else only the device operations
+ $35 : get interrupt vector
+ call:
+ AH: $35
+ AL: interrupt number
+ return:
+ ES:BX: pointer to interrupt routine
+ $36 : get disk free space
+ call:
+ AH: $36
+ DL: drive (0=default, .....)
+ return:
+ BX: available clusters
+ DX: clusters per drive
+ CX: bytes per sector
+ AX: $FFFF=drive number invalid
+ otherwise sectors per cluster
+ $38 : return country-dependent information
+ call:
+ AH: $38
+ DS:DX: pointer to 32 byte memory area
+ area format:
+ size name
+ 2 date/time format
+ 0=usa standard h:m:s m/d/y
+ 1=europe standard h:m:s d/m/y
+ 2=japan standard y/m/d h:m:s
+ 5 asciz currency symbol
+ 2 asciz thousands separator
+ 2 asciz decimal separator
+ 2 asciz date separator
+ 2 asciz time separator
+ 1 bit field
+ bit 0: 0=currency symbol precedes amount
+ 1=symbol comes after amount
+ bit 1: 0=symbol immediately precedes the amount
+ 1=space between symbol and amount
+ 1 currency places
+ figures after decimal point of currency amounts
+ 1 time format
+ 0=12 hour time
+ 1=24 hour time
+ 4 case mapping call
+ FAR procedure performs country-specific
+ lower- to uppercase mapping
+ 2 asciz data list separator
+ if dx=-1 and the country code in AL is found,
+ the current country is set accordingly
+
+ AL: function code
+ 0=current country
+ or country code (usually international telephone prefix)
+ must be 0 in msdos 2.0 (only fully implemented after 2.01)
+ return:
+ CARRY: 1
+ AX: 2=file not found
+ CARRY: 0
+ DS:DX: filled with country data
+ $39 : create subdirectory
+ call:
+ AH: $39
+ DS:DX: pointer to pathname (asciz)
+ return:
+ CARRY: 1
+ AX: 3=path not found
+ 5=access denied
+ no room in parent,
+ directory already exists or device was specified
+ CARRY: 0=no error
+ $3A : remove a directory entry
+ call:
+ AH: $3A
+ DS:DX: pointer to pathname (asciz)
+ return:
+ CARRY: 1
+ AX: 3=path not found
+ 5=access denied
+ directory not empty, not a directory, root directory
+ 16=current directory
+ CARRY: 0=no error
+ $3B : change the current directory
+ call:
+ AH: $3B
+ DS:DX: pointer to pathname (asciz)
+ return:
+ CARRY: 1
+ AX: 3=path not found
+ CARRY: 0=no error
+ $3C : create a file
+ call:
+ AH: $3C
+ DS:DX: pointer to pathname
+ CX: file attribute
+ return:
+ CARRY: 1
+ AX: 3=path not found
+ 4=too many open files
+ file was created, but no room for handle
+ 5=access denied
+ uncreatable attribute (directory or volume id),
+ a file with a more inklusive attribute set exists,
+ or a directory with the same name exists
+ CARRY: 0
+ AX is handle number
+ handle is open for read/write
+ creates a new file or truncates existing to length 0
+ $3D : open a file
+ call:
+ AH: $3D
+ DS:DX: pointer to pathname (asciz)
+ AL: access
+ 0=open for reading
+ 1=open for writing
+ 2=open for both
+ return:
+ CARRY: 1
+ AX: 2=file not found
+ 4=too many open files
+ no file handles available
+ 5=access denied
+ attempted to open a directory, volume id or
+ a read only file for writing
+ 12=invalid access
+ AL was not in range 0..2
+ CARRY: 0
+ AX is handle number
+ read/write pointer is set to the first byte of the file
+ and the record size is set to 1
+ the returned file handle must be used in subsequent operations
+ $3E : close a file handle
+ call:
+ AH: $3E
+ BX: file handle
+ return:
+ CARRY: 1
+ 6=invalid handle (not currently open)
+ CARRY: 0=no error
+ the associated file is closed, buffers are flushed
+ $3F : read from file/device
+ call:
+ AH: $3F
+ DS:DX: pointer to buffer
+ CX: bytes to read
+ BX: file handle
+ return:
+ CARRY: 1
+ AX: 5=access denied
+ not opened for read
+ 6=invalid handle (not currently open)
+ CARRY: 0
+ AX: number of bytes read
+ 0=eof
+ $40 : write to file/device
+ call:
+ AH: $40
+ DS:DX: pointer to buffer
+ CX: bytes to write
+ if 0, the file size is set to the current position
+ BX: file handle
+ return:
+ CARRY: 1
+ AX: 5=access denied
+ 6=invalid handle
+ CARRY: 0
+ AX: number of bytes written
+ is error if not the same number as requested
+ $41 : delete a directory entry
+ call:
+ AH: $41
+ DS:DX: pointer to pathname
+ return:
+ CARRY: 1
+ AX: 2=file not found
+ 5=access denied
+ directory or read only
+ CARRY: 0=no error
+ $42 : move file pointer
+ call:
+ AH: $42
+ CX:DX: distance to move, in bytes
+ AL: method of moving
+ 0=move pointer to offset from beginning of file
+ 1=move to offset from current location
+ 2=move to offset from eof
+ BX: file handle
+ return:
+ CARRY: 1
+ AX: 1=invalid function
+ AL not in range 0..2
+ 6=invalid handle
+ CARRY 0:
+ DX:AX: new pointer location
+ moves the read/write file pointer
+ $43 : change attributes
+ call:
+ AH: $43
+ DS:DX: pointer to pathname (asciz)
+ AL: function
+ 0=return in CX
+ 1=set to CX
+ CX: if AL=1
+ attribute to be set
+ return:
+ CARRY: 1
+ AX: 1=invalid function
+ AL not in range 0..1
+ 3=path not found
+ 5=access denied
+ CX contained attributes that can not be changed
+ (directory, volume id)
+ CARRY: 0
+ if AL=0
+ CX: attributes
+ $44 : i/o control for devices
+ call:
+ AH: $44
+ BX: handle
+ BL: (for calls AL=4, 5) drive: 0=default, ..
+ DS:DX: data or buffer
+ CX: bytes to read or write
+ AL: function code
+ calls 0,1: bits of DX (DH must be 0 on a set call)
+ 0: iscin
+ 1: iscot
+ 2: isnul
+ 3: isclk
+ 4: specl
+ 5: raw
+ 6: eof
+ 7: isdev
+ 8-13: reserved
+ 14: ctrl
+ 15: res
+ if isdev=0 then channel is a disk file
+ eof: 0=channel has been written
+ bits 0-5 are block device number for the channel
+ (0=a, 1=b, ..)
+ if isdev=1 then channel is device
+ eof : 0=end of file on input
+ raw : 0=this device is cooked
+ 1=device in raw mode
+ isclk: 1=clock
+ isnul: 1=nul
+ iscot: 1=console output
+ iscin: 1=console input
+ specl: 1=device is special
+ ctrl : 0=device can not do control strings
+ via calls 2,3
+ 1=can do control
+ 0=get device information (returned in DX)
+ 1=set device information (according to DX)
+ calls 2,5: arbitrary control strings sent or received
+ to or from a device
+ call syntax is the same as in read/write calls,
+ except for 4 and 5, which take drive number in BL
+ instead of a handle in BX
+ an invalid function error is returned, if
+ the ctrl bit is 0
+ 2=read CX number of bytes to DS:DX from device control channel
+ 3=write CX number of bytes from DS:DX to device control channel
+ 4=read CX number of bytes to DS:DX from device control channel
+ drive number in BL (0=default, ..)
+ 5=write CX number of bytes from DS:DX to device control channel
+ drive number in BL (0=default, ..)
+ calls 6,7: check, if a file handle is ready for i/o
+ intended for status of handles associated with
+ devices, but checks of file handles are allowed
+ and defined: input: always ready (255), until eof
+ then always not ready (0)
+ output: always ready
+ 6=get input status
+ 7=get output status
+ return:
+ CARRY: 1
+ AX: 1=invalid function
+ 5=access denied
+ 6=invalid handle
+ 13=invalid data
+ CARRY: 0
+ AL: 2,3,4,5
+ AX: count transferred
+ AL: 6,7
+ 0=not ready
+ 255=ready
+ sets or gets device information associated with an open handle
+ or sends or receives a control string to or from a device handle or device
+ if the function is used for files, only functions 0,6,7 are defined
+ $45 : duplicate a file handle
+ call:
+ AH: $45
+ BX: file handle
+ return:
+ CARRY: 1
+ AX: 4=too many files open
+ 6=invalid handle
+ CARRY: 0
+ AX: new file handle
+ retruns a new handle that refers to the same file
+ $46 : force a duplicate of a handle
+ call:
+ AH: $46
+ BX: existing file handle
+ CX: new file handle
+ return:
+ CARRY: 1
+ AX: 4=too many open files
+ 6=invalid handle
+ CARRY: 0=no error
+ CX then refers to the same file as BX, eventually, CX is closed first
+ $47 : return text of current directory
+ call:
+ AH: $47
+ DS:SI: pointer to 64 byte area
+ DL: drive number (0=default, ..)
+ return:
+ CARRY: 1
+ AX: 15=invalid drive
+ CARRY: 0=no error
+ the path name does not contain the leading separators
+ $48 : allocate memory
+ call:
+ AH: $48
+ BX: size of memory to be allocated
+ return:
+ CARRY: 1
+ AX: 7=arena trashed
+ internal consistency has been destroyed
+ 8=not enough memory
+ BX: maximum size that could be allocated
+ CARRY: 0
+ AX:0: pointer to the allocated memory
+ $49 : free allocated memory
+ call:
+ AH: $49
+ ES: segment address of memory area to be freed
+ return:
+ CARRY: 1
+ AX: 7=arena trashed
+ internal consistency has been destroyed
+ 9=invalid block
+ the block was not allocated by $49
+ CARRY: 0=no error
+ returns a piece of memory to the system pool that was allocated with $49
+ $4A : modify allocated memory blocks
+ call:
+ AH: $4A
+ ES: segment address of memory area
+ BX: requested memory area
+ return:
+ CARRY: 1
+ AX: 7=arena trashed
+ internal consistency has been destroyed
+ 8=not enough memory
+ 9=invalid block
+ the block was not allocated by $49
+ BX: maximum size possible
+ CARRY: 0=no error
+ attempts to grow or shrink an allocated block
+ $4B : load and execute a program
+ call:
+ AH: $4B
+ DS:DX: pointer to pathname (asciz)
+ ES:BX: pointer to parameter block
+ for AL=0:
+ size name
+ 2 segment address of environment
+ 4 pointer to command line at $80
+ 4 pointer to default fcb to be passed at $5C
+ 4 pointer to default fcb to be passed at $6C
+ for AL=3:
+ size name
+ 2 segment address where file will be loaded
+ 2 relocation factor to be applied to the image
+ AL: 0=load and execute
+ 3=load (overlay)
+ return:
+ CARRY: 1
+ AX: 1=invalid function
+ AL was not in range 0,3
+ 2=file not found
+ 8=not enough memory
+ 10=bad environment
+ larger than 32K
+ 11=bad format
+ EXE file contained inconsistent information
+ CARRY: 0=no error
+ all open files of a parent are copied to the child process
+ also inherited is an environment (block of text strings less than 32K)
+ a zero environment address causes the child to inherit then parents
+ environment unchanged
+ $4C : terminate process
+ call:
+ AH: $4C
+ AL: return code
+ $4D : retrieve then return code of a child
+ call:
+ AH: $4D
+ return:
+ AX: exit code
+ high byte: 0=terminate/abort
+ 1=alt-c
+ 2=hard error
+ 3=terminate and stay resident
+ returns code only once
+ $4E : find match file
+ call:
+ AH: $4E
+ DS:DX: pointer to pathname
+ CX: search attributes
+ return:
+ CARRY: 1
+ AX: 2=file not found
+ 18=no more files
+ CARRY: 0=no error
+ data block is written to current dma address:
+ size name
+ 21 reserved for subsequent calls
+ 1 attribute found
+ 2 time
+ 2 date
+ 2 low(size)
+ 2 high(size)
+ 13 packed name
+ subsequent calls: see $4F
+ $4F : step through a directory matching files
+ call:
+ AH: $4F
+ return:
+ CARRY: 1
+ AX: 18=no more files
+ CARRY: 0=no error
+ only used for subsequent calls after $4E
+ dma address must point to the parablock
+ $54 : return current setting of verify after write flag
+ call:
+ AH: $54
+ return:
+ current verify flag value
+ $56 : move a directory entry
+ call:
+ AH: $56
+ DS:DX: pointer to pathname of existing file
+ ES:DI: pointer to new pathname
+ return:
+ CARRY: 1
+ AX: 2=file not found
+ 5=access denied
+ path is directory or new file exists
+ or directory entry could not be created
+ 17=not same device
+ CARRY: 0=no error
+ attempts to rename a file in the directory of one device
+ $57 : get/set date/time of file
+ call:
+ AH: $57
+ AL: 0=get date and time
+ 1=set date and time
+ BX: file handle
+ CX: if AL=1
+ time to be set
+ DX: if AL=1
+ date to be set
+ return:
+ CARRY: 1
+ AX: 1=invalid function
+ 6=invalid handle
+ CARRY: 0=no error
+ CX: if AL=0
+ time
+ DX: if AL=0
+ date
+ date and time are not recorded until file is closed
+
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