[comp.sys.ibm.pc] VGA problems

elrond@titan.tsd.arlut.utexas.edu (Brad Hlista) (07/14/89)

I am considering keeping my Orchid VGA Prodesigner and Mitsubishi Diamond
Scan if I can get them to work together.  My problem is definately the VGA
or the monitor cable.  If anyone has such a setup and had to do something
special, please let me know.  I returned my VGA and now have a loner (other 
brand).  New Orchid cards are due in next week at the local shop and I will
learn whether or not I had a bad card.  Solutions will be accepted, thanks.
	elrond@128.83.145.81

gaia@portia.Stanford.EDU (fai to leung) (07/19/89)

Help!

Does anyone know how to lock VGA to CGA or Mono Mode that survives reboot?

uri@arnor.UUCP (Uri Blumenthal) (07/21/89)

From article <3768@portia.Stanford.EDU>, by gaia@portia.Stanford.EDU (fai to leung):
> 
> Does anyone know how to lock VGA to CGA or Mono Mode that survives reboot?
Yes. If you have, for example, Paradise VGA - there's set of utilities,

want. Then CGA will survive soft reboot (<CTRL><ALT><DEL>), but not
power-down of course. The utility name is something like VGA, or
whatever. There's not so many *.EXE to get lost. Also each VGA card
has its own "special" set of utilities - mine probably won't work
on yours.

Uri.
---------------------
<Standard Disclaimer>

gene@cooper.cooper.EDU (Gene (the Spook) ) (07/21/89)

in article <3768@portia.Stanford.EDU>, gaia@portia.Stanford.EDU (fai to leung) says:
> Xref: cooper comp.sys.ibm.pc:27483 alt.msdos.programmer:121
> 
> 
> Help!
> 
> Does anyone know how to lock VGA to CGA or Mono Mode that survives reboot?

The only solution I know of is from Paradise Systems. I've got a Paradise
VGA Plus 16, and one of the supporting programs lets you lock into a
particular mode even after rebooting.  Hope that helps at least a little.

							Gene

tris@alzabo.uucp (Tris Orendorff) (07/23/89)

This is easy to do with some VGA cards and impossible with others.
It can be done with a Paradise Plus or Plus 16 card using the vga.exe
program supplied on a floppy.

-- 
				Sincerely Yours
				Tris Orendorff

.......................................................................

d86-tpl@nada.kth.se (Tomas Prybil) (11/03/89)

Hi netlanders!

I'm trying to write a piece of code that would dump a VGA (640*480) 
picture to disk as fast as possible. Im interested to do the opposite 
as well.

The video buffer according to detecting software starts at 0xB000:8000.
I thought that it would be possible to set up a pointer to the adress
and then write from the starting adress + 64k out to disk. This was 
apparently NOT the way to do it! But how should I do?

There are probably many out there who knows how to do it and I would
really appreciate any hint or source (C Pascal or ASM).

Have a nice day!!

  tomas prybil
  student of above org.

ben@val.uucp (Ben Thornton) (11/03/89)

d86-tpl@nada.kth.se (Tomas Prybil) writes:

>Hi netlanders!

>I'm trying to write a piece of code that would dump a VGA (640*480) 
>picture to disk as fast as possible. Im interested to do the opposite 
>as well.

>The video buffer according to detecting software starts at 0xB000:8000.
>I thought that it would be possible to set up a pointer to the adress
>and then write from the starting adress + 64k out to disk. This was 
>apparently NOT the way to do it! But how should I do?

First of all, if you are referring to 640x480x16 color GRAPHICS mode,
(mode 12H), then the display buffer starts at A000:0.

Further:
The display memory in 640x480x16 is split into 4 separate planes.  It takes
4 bits of information to determine the color of each displayed pixel, and
each plane provides 1 bit each of that information.  However, when reading
and writing to the display memory, you have to set up the plane enable
bits (I forget the register name) to determine which plane you wish to
read from or write to.  In write mode, you can enable ALL of them if you
want all the planes to contain the same pattern of bits.  In this case,
a 1 would make color 15 while a 0 would make color 0.

In read mode you can enable only 1 plane at a time (for obvious reasons).
The easiest thing to do is enable plane 0, read 64k starting at A000:0
enable plane 1, read 64k starting again at A000:0, etc. for all 4 planes.

>  tomas prybil
>  student of above org.
-- 

Ben Thornton             packet:  WD5HLS @ KB5PM
Video Associates Labs      uucp:  ...!cs.utexas.edu!oakhill!val!ben
Austin, TX              fidonet:  1:382/40 - The Antenna Farm BBS

csirmaz@porthos.rutgers.edu (Laszlo Csirmaz) (11/08/89)

In article <2256@draken.nada.kth.se> d86-tpl@nada.kth.se (Tomas Prybil) writes:

> I'm trying to write a piece of code that would dump a VGA (640*480) 
> picture ...
> I thought that it would be possible to set up a pointer to the adress
> and then write from the starting adress + 64k out to disk....
> 

A question to the wizards of the network: 
   Can I give a VGA memory pointer directly to the hard disk controller 
to copy from (or to) say, 64k bytes? And do the DMA transfer work
perfectly in the VGA display memory, too?

Please send mails to me:

			Laci

celt@portia.Stanford.EDU (Michael Minakami) (11/09/89)

In article <2256@draken.nada.kth.se> d86-tpl@nada.kth.se (Tomas Prybil) writes:

> I'm trying to write a piece of code that would dump a VGA (640*480) 
> picture ...
> I thought that it would be possible to set up a pointer to the adress
> and then write from the starting adress + 64k out to disk....

That method works for screen sizes <64k, but in most modes on VGA
adapters video memory is divided into 64K pages. You need to save each
page...now a question for the tech wizards: How do you select which page
is accessible?