The screen physical device driver cannot accurately identify the size of the video memory for all adapters. This is because all of the necessary information for some of the adapters cannot be obtained in protect mode. In order to solve this problem, the Super VGA base video handler updates its memory information by calling the IOCtl. Information supplied to the IOCtl is obtained from the SVGADATA.PMI file.

If you run applications that use this IOCtl to modify the video memory size, be aware that there is no mechanism for identifying changes to other applications that previously used Function 08h to obtain video memory size.