OSDev.org

>On 2001-09-29 17:03:58, Stefan wrote:
>For changing to a VESA must I make use of int 10h allways?
>Thanks!

A bit late maybe. Answering two weeks after you asked the question but anywany I'll answer it.

The answer that j:weeks guy was incorrect. You can use the VESA interface without using RM INT 0x10.
Instead you should use a call gate through PMODE.
For info on how to do it check out the VBE 2.0 or VBE 3.0 specification, it can be downloaded at various hardware related sites or ordered from VESA.

>A bit late maybe. Answering two weeks after you asked the question but anywany I'll answer it.
>
>The answer that j:weeks guy was incorrect. You can use the VESA interface without using RM INT 0x10.
>Instead you should use a call gate through PMODE.
>For info on how to do it check out the VBE 2.0 or VBE 3.0 specification, it can be downloaded at various hardware related sites or ordered from VESA.

Uhm... yeah, there's a protected mode interface (if the
cards supports it!) but you need int 10h to GET IT!

Also, if you're only supporting the pmode interface,
you'll be eliminating a lot of cards that you support.
You should support the standard vesa 1.2 stuff,
requires int 10h exclusively.

"that j:weeks guy"

>On 2001-10-15 08:55:32, Anonymous wrote:
>>On 2001-09-29 17:03:58, Stefan wrote:
>>For changing to a VESA must I make use of int 10h allways?
>>Thanks!
>
>The answer that j:weeks guy was incorrect. You can use the VESA interface without using RM INT 0x10.

You can't switch video modes without INT 0x10
unless you write your own pmode driver.

>For info on how to do it check out the VBE 2.0
>...

The protected mode functions supplied by VBE 2.0
are pretty useless, IMO. There's a pmode function
to change banks, but VBE 2.0 also supplies a
linear framebuffer, so why do you need banking?
There a pmode function to change the 256-color
palette, but the palette is usually compatible
with VGA, so you can just write I/O ports
0x3C8 and 0x3C9 instead.

I don't know what's new in VBE 3.0

>You can't switch video modes without INT 0x10
>unless you write your own pmode driver.

Exactly!

>The protected mode functions supplied by VBE 2.0
>are pretty useless, IMO. There's a pmode function
>to change banks, but VBE 2.0 also supplies a
>linear framebuffer, so why do you need banking?

Some cards don't support a linear frame buffer,
apparently. Why? I couldn't tell you, but I've
programmed a few cards that support the pmode
interface, but no frame buffer. Kinda weird (ie,
stupid

>There a pmode function to change the 256-color
>palette, but the palette is usually compatible
>with VGA, so you can just write I/O ports
>0x3C8 and 0x3C9 instead.

Yeah, I don't know what that's all about. Vesa
2.0's strange about that stuff... and most
cards don't even support it now-a-days, so...

>I don't know what's new in VBE 3.0

What what I've heard, just a "standard" for
accessing 3d hardware.

j.weeks

Thank you!
But your answers don't please me!
Perhaps you now a link or a doc about TNT graphic processors, because I have
a Vanta witch support VESA 3.0!
I don't like to work with INT interrupts, that's why
I am looking for some documentation about changing graphic
mode without INT 0x10!

>On 2001-10-19 18:09:41, Stefan wrote:
>Thank you!
>But your answers don't please me!

.

>Perhaps you now a link or a doc about TNT graphic processors, because I have
>a Vanta witch support VESA 3.0!

Search for VGADOC on the web. It's got low level
details on a lot of video cards. I can't
garauntee that includes the TNT, but I would think
it probably does.

>I don't like to work with INT interrupts, that's why
>I am looking for some documentation about changing graphic
>mode without INT 0x10!

Why don't you want to use ints? It's easier, and
will support more cards.

Granted, supporting cards directly will be faster,
but it's a lot of work (something to be done
later on, when the OS is close to completion (in
my opinion, anyway))

j.weeks