Screen Modes

[srg]

Hi
How do I change screen modes without using DOS or BIOS calls, so going to the hardware it's self. Also what about this 50 line mode, is that just a DOS hack, or can I implement it myself?

Thanks

[srg]

There must be some way of doing it!! All examples I've found use BIOS.

[Krom]

You can, you must use directly the ports of the VGA(or any other card). The problem is that you must do a lot of things. The easy way is using BIOS, but if you wants to do it in pmode, i think the VESA 2.0+ have pmode functions u can use.

About the 50 lines mode is not a DOS hack, they do it changing the VGA registers(trought the ports, of course)

[srg]

I think I shall come back to that at a later date, as I don't plan to use VESA yet, just VGA.

BTW Do you know of any places where I can find out exactly what I need to do, using the ports, to change video mode. I can then go back to that as a reference. Or, I do have the source of the linux kernel 2.4, where would it be in that?

Thanks

[crazybuddha]

I think this has been answered on this forum, possibly even by me. Do a search and see where it takes you. In VGA, it's fairly simple to do once you understand how the video registers work.

[srg]

found it

What is that initalised data all for?

[crazybuddha]

without a reference, I can't be 100% sure of what you mean, but I think you're talking about the values which are fed to ports. There is a good explanation of the ports somewhere. I'll see if I can dig it up as soon as I get a chance.

[crazybuddha]

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