mov ax, 1A00h ;Get ANSI.SYS Installed State
int 2Fh ;Multiplex Interrupt
cmp al, 0FFh ;0FFh means installed
Get ANSI.SYS Installed State (Interrupt 2Fh Function 1A00h) determines whether the ANSI.SYS device driver has been loaded.
This function has no parameters.
The AL register contains 0FFh if ANSI.SYS has been loaded or 00h if it has not.