Newsgroups: comp.os.msdos.djgpp From: adam AT videodatasys DOT com (Adam Meyerowitz) Subject: VGA,PCI and Dos Extender X-Newsreader: MicroPlanet Gravity v2.10 X-Complaints-To: Email abuse AT news2 DOT new-york DOT net if this posting is inappropriate Nntp-Posting-Host: x2haup34.asb.com Message-ID: X-Trace: news2.new-york.net 915546577 5134 (None) [165.254.199.34] Date: Tue, 5 Jan 1999 14:27:26 GMT To: djgpp AT delorie DOT com DJ-Gateway: from newsgroup comp.os.msdos.djgpp Reply-To: djgpp AT delorie DOT com Hello, Maybe someone can shed some light on this. I'm programming in a dos extender (Pharlap TNT RealTime) and trying to write to a PCI VGA card by mapping the linear frame buffer into the programs data segment. Basically this is what I do. 1. Get the Physical Address Pointer to the linear frame buffer by using a VESA call. I confirm this is correct by comparing it to the value returned from PCI Bios Calls. 2. Map the linear frame buffer into the program's data segment 3. Change the video mode by using VESA Calls (4f02 or something like that). 4. Use the pointer returned from 2 to write into the memory. All this sounds correct but nothing happens besides the change of the video mode. I cannot see any output on the vga. Any hints or suggestions? Thanks Adam Meyerowitz Video Data Systems