Q19842: How Microsoft BASIC ON ERROR Handles DOS General Drive Failure

Article: Q19842
Product(s): See article
Version(s): 6.00 6.00b 7.00
Operating System(s): MS-DOS
Keyword(s): ENDUSER | B_QuickBas | mspl13_basic
Last Modified: 2-FEB-1990

Error trapping in Microsoft BASIC programs (invoked with the ON ERROR
statement) will trap a DOS general drive failure.

A DOS general drive failure occurs if an error occurs while trying to
read the specified drive (for example, the drive door is not closed or
the disk is improperly formatted). The general drive failure message
is usually of the following form:

   General failure reading drive A:
   (Abort, Retry, Ignore)?

BASIC error trapping invoked with the BASIC ON ERROR statement traps
the DOS general drive failure and returns a BASIC error number 57,
"Device I/O error."