[Oberon] VESA code removed in Bluebottle?
Salewski at PHYSnet.Uni-Hamburg.de
Fri Apr 2 16:42:56 CEST 2004
Am Freitag, 2. April 2004 14:23 schrieb Daniel Keller:
> As far as I understand, each vesa mode has an assigned refresh
> rate. There is no way to run mode "11A" with 100 Hz. Your graphic
> adapter is supposed to support at least a dozen of VESA2 modes.
> Choose your favourite one.
> But ask fischer at inf.ethz.ch for more details. He has implemented
> Bb's bootloader and is familiar with VESA.
> VESA 3.0 is not yet supported. If you are going to implement it,
> drop us your code;-)
I have a printout of the VESA BIOS EXTENSION (VBE) Manual, Version
3.0. It is freely available at www.vesa.org (which is not the case
for all VESA-Documentation.)
Yes, screen-resolution up to 1280x1024 can be selected in a simple way
using code-numbers. I think this was the way before VESA 3.0, and it
gives default refresh rates, which is only 60 Hz for my Matrox G450.
Vesa 3.0 allows even higher screen resolution and arbitrary refresh
rate, but programming this is much more complicated. In the
VESA-Manual strange terms like "FAR-POINTER", NEAR-POUNTER", "REAL
MODE", "PROTECTED MODE" occur. So extending VESA-Code is not a simple
task. But there was module DisplayLinear.mod in last release of
Native-Oberon with much VESA-3.0-Code (if I remember correctly).
Maybe we can port this to BlueBotttle.
If I should decide to go on playing with Bluebottle, then I have to do
something against the 60 Hz flicker of my CRT.
The fastest and simplest solution is to use a 1280x1024 TFT. We have
a few here in the institute, maybe I can exange my CRT.
Having a working VESA-3.0-Display-Driver seems to be very important
for BlueBottle, but I am not sure if I will be able to do it. Not too
much time, not much knowledge about dirty low level 80x86
hardware-programming, and no one like Pieter Muller behind me.
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