Compatibility: 2.0+
Purpose: This causes DOS to enable or disable a low-level disk function
which checks each disk sector after it is written.

The Verify command does the same thing

Syntax: VERIFY=ON
or: VERIFY=OFF

  Parameters  

ON turns on write-verification (maximum safety).

OFF turns it off (better speed).

The default setting is VERIFY=OFF.

  TECH Notes  

  You can do this in your program via DOS fn 2eH (set/reset verify).

  Verify ON does NOT compare written data to data in memory.  It performs
an INT 13H 04H (verify sectors) on data after it is written.  That fn
compares the ECC  recorded in the sector with the ECC calculated by the
controller.

  Internally, DOS toggles VERIFY ON when it writes FAT and directory
information.  Leaving VERIFY ON all the time will degrade disk
performance, especially on floppy diskettes.

- -

VERIFY= (CONFIG.SYS Command)