Framebuffer or standard VGA ?

Antony Stone Antony at
Wed Sep 11 03:46:01 CEST 2002

On Wednesday 11 September 2002 7:22 am, Steve M. Gehlbach wrote:

> > > Maybe someone knows if alphanumeric mode setup is via the standard VGA
> > > register set on most modern VGA cards.
> >
> > I am afraid your are wrong. For modern VGA cards, there is actually no
> > alphanumeric mode. These alphanumeric mode were simulated by BIOS or
> > drivers. The worst thing, if you have no documents about these extended
> > registers, you have no way to drive the clock gen for Dot clock, Hsync,
> > Vsync.
> Are you saying that it is not possible to use a text console with Linux
> (vgacon.c) with modern VGA cards (BIOS mode 3)? Only framebuffer? Or are
> you saying that without extra information (ie, the BIOS or the manuals) you
> can't init it into mode 3?

Excuse the second posting to this thread so soon after my last, but I've 
found a far more succinct way of expressing my point:

If I go out and buy the latest whizz-bang graphics card, just released onto 
the market, and plug it into my three year old PC, whose designers knew 
nothing abut today's graphics cards, I expect to see a text console screen 
when I turn it on.

This means one of two things.   Either:

1. there's a standard way for the motherboard Bios to initialise _any_ 
graphics card, so it can initialise a new one it's never heard of before (and 
presumably LinuxBios could do the same), or:

2. there's a standard init call to the bios chip on the graphics card, which 
knows how to set up that particular model, which again LinuxBios could 
perform in exactly the same way when it starts up ?

Is there a flaw somewhere in my reasoning ?



Behind the counter a boy with a shaven head stared vacantly into space,
a dozen spikes of microsoft protruding from the socket behind his ear.

 - William Gibson, Neuromancer

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