OS/2 adapter driver file used in the boot process
ADD is a file extension for an OS/2 adaptor driver file format used by the OS/2 boot process. OS/2 is an IBM operating system, introduced in 1987, that was intended to provide an alternative to Microsoft Windows for both enterprise and PC users.
Learn more about ADD files:
See Barbara Darrow’s article ‘Is IBM considering an OS/2 redo?’ at SearchDataCenter.com.
Search for answers to ADD-related questions at IT Knowledge Exchange.