5F38h – Hook Before Set Mode

This hook allows the system BIOS to intercept the video BIOS before setting the mode.

Calling Registers:

AX = 5F38h, Hook Before Set Mode

CL = New video mode to be set

Return Registers:

AX = Return Status (function not supported if AL != 5Fh):

= 015Fh, Function supported but failed

= 005Fh, Function supported and successful