First post, by Falcosoft
I have noticed that one of the more important VESA (VBE) functions always fails on my Geforce GTX 960. I could also reproduce the bug on a GTX 1060.
The buggy function is this:
Function 07h - Set/Get Display Start.
This is a required function at least form VBE 1.2 and used for implementing virtual scrolling and hardware double/triple buffering (so it's an important one).
The function is reported as supported but always fails on the tested cards. I would like to get some help to find out whether all the NVIDIA cards in these newer series are affected and in which series the bug appeared.
I have written a little test (VBEVSTST.EXE attached, source code included) that can be used to discover if a card is affected. After staring the program in DOS/Win9x/XP you just have to press the arrow keys. If Set/Get Display Start is working then you will see the screen moving in the corresponding directions and also you can see some info about the function call success.
Also Scitech Display Doctor(UniVbe)'s VBETEST.EXE can be used for testing. Both the virtual scrolling and double buffering test fail if the card is affected (more precisely the double buffering test is 'working' but you will see flickering screen and always 'Page 1 of x' info instead of paging).
Thanks in advance for your help.
!!! For Geforce 4xx and 5xx series users: Please, help us by testing your cards since this way we can identify the first generation of cards where this bug appeared. Thanks !!!
There is now a workaround available (in the form of my MSKVBEF7 patch/TSR) that according to tests fix problems at least with Quake1 and Build engine games ( Blood and DND3D tested).