From: Martin Eli Erhardsen <mee@daimi.aau.dk>
  To  : ggi-develop@eskimo.com
  Date: Wed, 29 Jul 1998 18:48:46 +0200

Re: I've seen the stars too... [Re: kgicon, etc]

Rodolphe Ortalo wrote:
> 
> Geert Uytterhoeven wrote:
> >FYI: clgenfb (the Cirrus Logic driver for Amiga m68k and APUS) is in the vger
> >tree... Add some PCI probing and it should work.
> 
> Hmmm. Geert, I've got a running kgi driver for nearly a year now...
> Furthermore, I guess you are speaking of the 542x chipset series from
> Cirrus Logic.
> (BTW: the kgi driver from Martin should work on these chipsets too, provided
> you remove the VGA IO region claim.)

I have just patched my 542x driver to work with kgicon, and commited to
CVS.

My only problem with kgicon is that scrolling is REALLY SLOW.
I could almost read the lines as they scrolled down the screen when
doing
a cat of a text file on my P133. 
The normal textmode console is over 100 times faster.

How is it possible to write a scroller which is so slow.
Does it copy the whole screen in the framebuffer every time.

Most hardware supports setting the start adress of the display, which
really
would speed up the scrolling. The VGA splitline helps too, but you can
do
without it, if you use a virtual screen larger than the physical one,
because
you then don't have to copy the screen every time. If you for example
add 5
extra lines of text, them you only have to do a copy every fifth time.
This really speeds everything up, because reading from video memory is
slow.