OSDev.org

I want to write a software that use INT 10h function 4f10h to set display power state to off but this function(4f10h) don't work! Why this happen? I too want create a software that set a pixel clock! What can I do?

If you want to turn the display off (like, power off), use APM. It's more standard and supported than VBE, albeit a little buggy on some BIOSes.