Compatibility: 3.0+

Expects: AH    59H

BX    0000H (need for 3.x and 4.x)

Returns: AX    extended error code (0 if no error has occurred)

BH    error class

BL    suggested action

CH    location (where the error occurred)

Info: Use this function to figure out what to do after a DOS function

failed because of an error.  You can use this:

  Inside an INT 24H Critical Error handler

  After any INT 21H DOS function which signals an error with CF

  After FCB-style functions which return AL=ffH means an error

See DOS Error Codes for a full listing of possible error codes,

classes, suggested actions, and loci that may be returned by this

function.

Notes:   After an error, you get only on chance to call this fn.  After

one call, the error condition is unflagged and subsequent calls

won't return meaningful data.

  You can use fn 5D0aH to simulate an error or set your own

internal error codes.

Versions: This function is not available before 3.00.

With 2.x, when CF returns indicating an error, use your own

program logic to decide what action to take.

With 3.0+, when a function returns CF=1, Microsoft advises to

ignore the error code returned in AX, call this function, and

take the action suggested in BL.

See Also: Fn 5d0aH (set extended error)

System Information Functions

DOS Error Codes

DOS Functions

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