Function 59h (89)        Get Extended Error Information               DOS 3.0

Returns diagnostic information following an unsuccessful DOS function
call or Interrupt 24h.

On entry:      AH         59h
BX         0000h for DOS 3.0 and above

Returns:       AX         Extended error code
BH         Error class
BL         Suggested action
CH         Locus (Source of error)

Destroys:      CL, DX, SI, DI, ES, and DS are all changed

                                                                          

This function returns detailed diagnostic information about an error
condition. It can be used from inside a critical-error (Interrupt 24h)
handler; after a DOS function call that reports an error by setting
the Carry Flag; and after an FCB file operation that reports a return
code of FFh.

Values returned in AX (extended error code):

        AX    Extended error code              AX    Extended error code
01h   Invalid function number          14h   Unknown unit
02h   File not found                   15h   Drive not ready
03h   Path not found                   16h   Unknown command
04h   Too many open files              17h   Data error (CRC)
05h   Access denied                    18h   Bad request structure
06h   Invalid handle                         length
07h   Memory control blocks            19h   Seek error
destroyed                        1Ah   Unknown medium type
08h   Insufficient memory              1Bh   Sector not found
09h   Invalid memory block address     1Ch   Printer out of paper
0Ah   Invalid environment              1Dh   Write fault
0Bh   Invalid format                   1Eh   Read fault
0Ch   Invalid access code              1Fh   General failure
0Dh   Invalid data                     20h   Sharing violation
0Fh   Invalid disk drive               21h   Lock violation
10h   Attempt to remove current        22h   Invalid disk change
directory                        23h   FCB unavailable
11h   Not the same device              50h   File already exists
12h   No more files                    52h   Cannot make directory
13h   Disk is write-protected          53h   Critical error

Values returned in BH (error class):

           BX    Error class
01h   Out of resource
02h   Temporary problem that can be expected to go away
03h   Authorization (permission) problem
04h   Internal error (i.e., a system software bug)
05h   Hardware problem (not the fault of your program)
06h   System software failure (e.g. bad or missing CONFIG.SYS)
07h   Application program error
08h   File or other item not found
09h   File or other item of invalid or unsuitable format or type
0Ah   File or other item interlocked
0Bh   Media problem (e.g. CRC error, wrong disk in drive)
0Ch   Collision with existing item
0Dh   Other (unclassified)

Values returned in BL (suggested action):

           BL    Suggested action
01h   Retry a few times
02h   Pause, then retry
03h   Ask user to resupply input
04h   Abort with cleanup (orderly shutdown)
05h   Immediate abort (do not pass GO)
06h   Ignore
07h   Ask user for remedial action (e.g. insertion of
diskette), then retry

Values returned in CH (source of error):

           CH    Source of error
01h   Unknown
02h   Block device (disk)
03h   Network
04h   Serial device
05h   Memory

Notes:         Since new error codes may be added from time to
time, your program should be able to gracefully
handle unrecognized error codes.

See also: INT 24h

59h (89) Get Extended Error Information >= DOS 3.0