VOGONS


First post, by PlaneVuki

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Newbie

Hello,

Assuming that there is no PC-bios how can I set VGA to mode13h (with default palette) ?

Because that is what I am trying to do: write my own program to a rom chip, and use it instead of the pc-bios chip on an old 286 computer.

Although there will be no pc-bios, but will there still be a VGA-bios, if yes how can it be used? How does VGA bios even get mapped to system?

What is the easiest way (or ways) to initialize and set VGA card to mode13h (320x200 resolution at 256 colors) ?

Help of experienced hardware assembly coders needed.

Thanks much in advance.

Reply 1 of 3, by BinaryDemon

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I have no experience with any of this, but I was thinking if I wanted to attempt something similar would probably take a look at some of the free open source BIOS replacements like: https://www.coreboot.org/

I’d look for the sections of code that initialize the video bios and copy the video rom to system ram.

Check out DOSBox Distro:

https://sites.google.com/site/dosboxdistro/ [*]

a lightweight Linux distro (tinycore) which boots off a usb flash drive and goes straight to DOSBox.

Make your dos retrogaming experience portable!