Re: GGI Project Unhappy On Linux

Geert Uytterhoeven (Geert.Uytterhoeven@cs.kuleuven.ac.be)
Fri, 27 Mar 1998 17:57:04 +0100 (CET)

On Fri, 27 Mar 1998, Pavel Machek wrote:
> > > > Would you like to see boot messages?
> > > No. I won't buy shitty cards designed for Windows 98. Just the same as I won't
> > > buy a GUI printer or WinModem. You will? They you'll be sorry.
> >
> > Then you won't have a PC fairly soon. Nobody needs text mode, people are
> > starting to emulate it by default and Linux has a fine frame buffer console
> > without KGI/GGI getting much involved. If you want to support Japanese on
> > the console I suspect it will also be somewhat useful (text mode is a bit
> > small in fonts).
>
> I've seen linux text-mode emulation on ultra-sparcs. There are not
> many machines faster than ultra. It is *slow* compared to my 486 with
> VGA. Even if you turn of hw scrolling on VGA it starts to be too

The main reason is that text scrolling is done in FORTH under Open Firmware,
which is an interpreted language (using FCode).

But there are many ways to accelerate scrolling, all supported by fbcon (on
some chipsets):

- memcpy with the CPU (slow, mainly due to limited memory bandwidth. The PCI
on my PPC is only 32 bit, 33 MHz). this is what is used if anything else
fails

- use a large virtual screen (e.g. 4000 pixels vertically) and pan, so you
only have to do a memcpy once every 4000/fontheight lines

- use ywrap (split screen)

- use the blitter on your graphics board

Greetings,

Geert

--
Geert Uytterhoeven                     Geert.Uytterhoeven@cs.kuleuven.ac.be
Wavelets, Linux/{m68k~Amiga,PPC~CHRP}  http://www.cs.kuleuven.ac.be/~geert/
Department of Computer Science -- Katholieke Universiteit Leuven -- Belgium




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