mov ax, 0B700h ;Get APPEND.EXE Installed State
int 2Fh ;Multiplex Interrupt
cmp al, 0FFh ;0FFh means installed
je installed
Get APPEND.EXE Installed State (Interrupt 2Fh Function 0B700h) determines whether the resident portion of the Append program has been loaded.
This function has no parameters.
The AL register contains 0FFh if the Append program has been loaded or 00h if it has not.