Roell X11R4 and paper white VGA
Thomas Roell
roell at informatik.tu-muenchen.dbp.de
Fri Dec 14 20:09:18 AEST 1990
>For other reasons, Herr Roell insists on programming the VGA in color
>mode. This saves and restores the CRT controller and other registers
>from and to ports 0x3D?.
Silly me.
>The result is that the VGA is totally hosed by the server. On return to
>the console VT after xinit, the text on the screen is a cloud of snow and
>/bin/su -c 'init 0' is the only way to go.
Calling vpix would do the same job.
>I have patches to X/mit/server/ddx/at386/vga/{vga.h,vgaHW.c,et4000/driver.c}
>which make it sensitive to the io port mapping of the VGA card and allow
>me to recover the VGA after xinit. I will post these soon.
Ok, everybody is welcome to send ME the patches, but in general, I like to
coordinate the work by myself. I allready worked on this problem, and got
a solution. It's now under beta-test. Other beta-testers are welcome.
But they must have a REAL GOOD KNOWLEDGE OF VGA-PROGRAMMING.
>Finally, a point of clarification about the [+-][hv]sync flags in Xconfig.
>
> flag bit result
> ----------------------------------------------
> +hsync 1 negative horizontal sync pulse
> -hsync 0 positive horizontal sync pulse
> +vsync 1 negative vertical sync pulse
> -vsync 0 positive vertical sync pulse
>
>The polarities of the sync pulses are used to signal the vertical resolution
>to the monitor. Roell's server automatically selects the correct sync
>polarities based on the vertical display size, but someone, namely me, who
>was trying to set the sync polarities explicitly found the results puzzling.
This is a TRUE bug. The meaning of +hsync is obviously a positive horizontal
sync pulse. This will also be fixed.
- Thomas
--
_______________________________________________________________________________
Mail: Thomas Roell (c/o Daniel Hernandez)
Inst. f. Informatik / Technische Universitaet M"unchen
Arcisstr. 21 / 8000 Munich 2 / Fed.Rep. of Germany
E-Mail (domain): roell at lan.informatik.tu-muenchen.dbp.de
UUCP (when above fails): roell at tumult.{uucp | informatik.tu-muenchen.de}
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