INT 10 - Tseng ET-4000 BIOS(Basic Input/Output System) A set of standardized calls giving low-level access to the hardware. The BIOS is the lowest software layer above the actual hardware and serves to insulate programs (and operating systems) which use it from the details of accessing the hardware directly. - GET/SET SCREEN REFRESH RATE AH = 12h BL = F1h AL = subfunction 00h set refresh rate 01h get refresh rate BH = video mode 00h 640x480 01h 800x600 02h 1024x768 03h 1280x1024 CX = new refresh rate (see #00035) if AL = 00h Return: AL = 12h if supported CX = current rate (for AL=00h, a changed CX indicates failure) (Table 00035) Values for Tseng ET4000 refresh rate: CX 640x480 800x600 1024x768/1280x1024 00h 60 Hz 56 Hz interlaced 01h 72 Hz 60 Hz 60 Hz 02h 75 Hz 72 Hz 70 Hz 03h 90 Hz 75 Hz 75 Hz 04h -- 90 Hz --