Hi, I would like to use INT22h, function 000Dh, but I found that it is disabled in vector table: in core/comboot.inc: int22_table: [...] dw comapi_err ; 000D clean up then bootstrap [...] The code of this function is present in this file (comapi_chainboot). Why this function is disabled? Regards Piotr Romaniuk PS I am using syslinux-4.04.