INT 2Fh (47)             Multiplex Interrupt (APPEND)                 DOS 3.1

Reports whether the resident part of APPEND is installed.

On entry:      AH         B7h
AL         00h

Returns:       AL         00h     Not installed, okay to install
01h     Not installed, not okay to install
FFh     Installed

See also: INT 2Fh...

INT 2Fh (47) Multiplex Interrupt (APPEND) >= DOS 3.1