From mboxrd@z Thu Jan 1 00:00:00 1970 To: 9fans@cse.psu.edu Subject: Re: [9fans] VGA and laptops Date: Tue, 26 Sep 2000 21:48:21 +0100 From: nigel@9fs.org MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Message-Id: Topicbox-Message-UUID: 0f6557ee-eac9-11e9-9e20-41e7f4b1d025 > I do have a question though, wasn't VESA compliance supposed to do away with > these problems It does, if you feel like you can put your trust in someone's BIOS.... Making a call into the BIOS is hairy in that you have no way to make it adhere to the particular set of rules which your operating system makes on drivers, e.g. time spent with interrupts off, how long spent spinning waiting for VBE etc.. As a result, one can imagine using it as a means to get the right screen mode at the start, but you would never think of making calls to it for accelerated drawing. So you can get a frame buffer and then bit bash, which I accept is a whole lot better than nothing. However, if you want an accelerated driver, then there are typically interrelationships between the screen mode, and the blitter, so VESA is not much help. Putting it another way, to be able to accelerate a chipset, you would probably need to understand every setting that VESA makes; if so, then why use it? VNH's native Inferno uses VESA calls to initialise the screen mode.