Error Codes

    All the FCB functions report an error by returning 0FFh in the AL
    register.  Other functions report an error by setting the carry flag
    and placing an error code in the AX register.  DOS 2.x functions
    return the error codes 0 - 12h.  Under DOS 3.x, it is best to call
    function 59h to obtain more detailed error information.

   CODE    Meaning
 Hex  Dec  ***********************
 00h  00.  No error
 01h  01.  Invalid function number
 02h  02.  File not found
 03h  03.  Path not found
 04h  04.  No handle available
 05h  05.  Access denied
 06h  06.  Invalid handle
 07h  07.  Memory control blocks destroyed
 08h  08.  Insufficient memory
 09h  09.  Invalid memory block address
 0Ah  10.  Invalid environment
 0Bh  11.  Invalid format
 0Ch  12.  Invalid access code
 0Dh  13.  Invalid data
 0Eh  14.  Reserved
 0Fh  15.  Invalid drive specification
 10h  16.  Attempt to remove current dir.
 11h  17.  Not same device
 12h  18.  No more files
 13h  19.  Disk write-protected
 14h  20.  Unknown unit
 15h  21.  Drive not ready
 16h  22.  Unknown command
 17h  23.  Disk data error (CRC)
 18h  24.  Bad request structure length
 19h  25.  Seek error
 1Ah  26.  Unknown media type
 1Bh  27.  Sector not found
 1Ch  28.  Printer out of paper
 1Dh  29.  Write fault
 1Eh  30.  Read fault
 1Fh  31.  General failure
 20h  32.  File sharing violation
 21h  33.  File locking violation
 22h  34.  Invalid disk change
 23h  35.  FCB unavailable
 24h  36.  Sharing buffer overflow
    .
    .      (Reserved)
    .
 26h  38.  Cannot complete file operation
    .
    .
    .
    .      (Reserved)
    .
    .
    .
 32h  50.  Network request not supported
 33h  39.  Remote computer not listening
 34h  40.  Duplicate name on network
 35h  41.  Network name not found
 36h  42.  Network busy
 37h  43.  Network device no longer exists
 38h  44.  Net BIOS command limit exceeded
 39h  45.  Network adapter hardware error
 3Ah  46.  Incorrect response from network
 3Bh  47.  Unexpected network error
 3Ch  48.  Incompatible remote adapter
 3Dh  49.  Print queue full
 3Eh  50.  Not enough space for print file
 3Fh  51.  Print file was deleted
 40h  52.  Network name was deleted
 41h  65.  Access denied
 42h  66.  Network device type incorrect
 43h  67.  Network name not found
 44h  68. Network name limit exceeded
 45h  69. Net BIOS session limit exceeded
 46h  70. Temporarily paused
 47h  71. Network request not accepted
 48h  72. Print or disk redirection paused
    .
    .
    .
    .      (Reserved)
    .
    .
 50h  80.  File exists
 51h  81.  Reserved
 52h  82.  Cannot make directory entry
 53h  83.  Critical-error interrupt failure
 54h  84.  Too many redirections
 55h  85.  Duplicate redirection
 56h  86.  Invalid password
 57h  87.  Invalid parameter
 58h  88.  Network device fault
 59h  89. Not supported by network
 5Ah  90. Required component not installed
  --------------------------------------------------------------------------

  The following information is returned by the DOS function 59h:

  Error class:

    Code    Meaning
     01h    Out of resource
     02h    Temporary situation; try again later
     03h    Authorization
     04h    Internal error in system software
     05h    Hardware failure
     06h    System failure; serious failure of system software
     07h    Application software error
     08h    Item requested not found
     09h    Bad format (e.g., unrecognizable disk)
     0Ah    Item locked
     0Bh    Media error (e.g., CRC error)
     0Ch    Already exists
     0Dh    Unknown

  Suggested action:

    Code    Meaning
     01h    Try again now.
     02h    Try again (a few times) after a pause, then prompt user to
            continue or abort.
     03h    Ask user to correct input, then retry.
     04h    Orderly abort; close files, then shut down the application.
     05h    Immediate abort; don't even try to close files.
     06h    Ignore.
     07h    Ask user to do something (like insert appropriate disk), then
            retry.

  Locus of error:

    Code    Meaning
     01h    Unknown
     02h    Block device (e.g., disk drive)
     03h    Network
     04h    Serial device
     05h    Memory