Re: Workaround for /dev/grf3 pixel clock only <29Mhz problem.

[Markus Illenseer <markus%core.de@localhost>]

On Wed, 27 Dec 2000, Petri Koistinen wrote:

> I found a workaround for the problem with /dev/grf3 that text console
> pixel clock could be only under 29Mhz.

 Which is, by any means, default for a true text mode since 1980 (Hercules
"graphic" board and EGA-boardss). Just about any PC displays this text
mode during BIOS warm-up.

 But the Amiga graphic boards commonly do not have a (E)(E)PROM with a
font stored on it. This is why we have to load a font into the graphic
board memory during initialisation of the board under NetBSD. (see "load
User Text font in your manual)

[...]
> Are text console modes real hardware text modes, or are they graphics
> modes with bitmapped fonts copied on screen. It would explain a lot.

 They are standard hardware text modes. Just any graphic chipset still
supports plain old text with on-chip text layout.

> Those who are interessed about Cirrus Logic 5446 databook may look at:
> http://iki.fi/thoron/amiga/gd5446trm.lha (pdf, package about 2,3MB).
> See page 8-44 (p. 265 in pdf file).

 See page 2.7 (2.3.3) for text modes, on page 3-24 (Chapter 3.1) for all
available modes, including text modes.

 I am pretty sure, we will not integrate your effort, because the patch
most probably will not work for all monitors (!) whereas it will certainly
work for all graphic boards (!). Sorry for that.

 BTW, while you are at it - you might want to look at my old screen switch
programm, which was used to switch between Amiga and Graphic Board modes.
It might be usefull to switch between different text modes as well. No,
sorry, I have no idea where I hide this tool... Any takers?

Markus Illenseer