Well, we have the windows piece, and then the fact that almost every PC BIOS on the planet needs VGA text mode and/or occasionally VGA graphics mode.
________________________________ From: Timothy Normand Miller <[email protected]> To: David Hilvert <[email protected]> Cc: [email protected] Sent: Fri, October 22, 2010 6:19:30 AM Subject: Re: [Open-graphics] Text mode notes That pretty much sums it up. Since Linux has a good graphical console, it's probably best to just stick with 80x25 until the kernel comes up. The main reason to support any more VGA (e.g. 640x480x16 graphics) is if we want to support Windows. We's also need good VBE support so we can get out of VGA emulation mode. OGD1 performance is really hurt in VGA mode, because our microcontroller becomes a communications bottleneck. It's best to avoid using it. On Fri, Oct 22, 2010 at 5:28 AM, David Hilvert <[email protected]> wrote: > Text mode seems to mostly work with OGD1 VGA BIOS version 0.1 tested on > OGD1 hardware under Ubuntu 10.10, with a few caveats -- > > VT100 frames (and others) don't seem to work (e.g., try aptitude on > Debian-like systems, links, or anything else that uses them). > > Setting text modes other than 80x25 sometimes works, but some modes have > apparently overstruck characters (i.e., produce obviously broken > output), while others appear at a size other than reported by GRUB. > > To enter other text modes, I used the 'linux16' and 'init16' commands > with GRUB2, enabling use of the kernel option 'vga=ask', which supplies > a list containing something similar to this: > > 0 F00 80x25 > 1 F01 80x50 > 2 F02 80x43 > 3 F03 80x28 > 4 F05 80x30 > 5 F06 80x34 > 6 F07 80x60 > > 80x25 and 80x30 produce nominal results, with 80x30 offering a larger > console size. 80x50 appears to produce an 80x25 character grid, with > larger characters overstruck with characters of a smaller size. 80x43 > and 80x60 produce a similar overstruck output, on 80x21 and 80x30 grids, > respectively. 80x28 produces an 80x24 mode with no obvious overstrike; > 80x34 produces an 80x29 mode with no obvious overstrike. > > In sum, the largest currently configurable grid via vga=ask appears to > be 80x30; other sizes that seem to work with reasonably rendered > characters are 80x25 (default), 80x24 (by selecting 80x28), and 80x29 > (by selecting 80x34). > > _______________________________________________ > Open-graphics mailing list > [email protected] > http://lists.duskglow.com/mailman/listinfo/open-graphics > List service provided by Duskglow Consulting, LLC (www.duskglow.com) > -- Timothy Normand Miller http://www.cse.ohio-state.edu/~millerti Open Graphics Project _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
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