Subject: Re: cg4 problems revisited...
To: None <>
From: Scott Ellis <>
List: port-sun3
Date: 07/15/1996 20:59:37
In "Re: cg4 problems revisited...", "Gordon W. Ross" <> wrote: 
> The hardware layout information came from the SunOS header file:
> /usr/include/sundev/cg4reg.h
> which appears to suggest there are two layouts for the cg4
> ("type A" and "type B").  My 3/60 has "type B".  Does yours?
> If we have to support both types, how do we determine which
> one we are looking at?
> Here are the relevant definitions from SunOS:
> /* A type (AMD DAC) definitions */
> #defineCG4A0
> /* frame buffer and color map addresses */
> #define CG4A_ADDR_OVERLAY0xFF000000
> #define CG4A_ADDR_ENABLE0xFE400000
> #define CG4A_ADDR_COLOR0xFE800000
> #define CG4A_ADDR_CMAP0x000E0000
> /* B type (Brooktree DAC) definitions */
> /* frame buffer and color map addresses */
> #define CG4B_ADDR_OVERLAY0xFF400000
> #define CG4B_ADDR_ENABLE0xFF600000
> #define CG4B_ADDR_COLOR0xFF800000
> #define CG4B_ADDR_CMAP0xFF200000

I did a quickie adjustment of cg4reg.h to be:

#define CG4REG_CMAP     0x0

#define CG4REG_OVERLAY  0x00C00000
#define CG4REG_ENABLE   0x00000000
#define CG4REG_PIXMAP   0x00400000

And now I do get an X display on the pixmap plane (hooray!).  Thanks for
offsets Gordon! (I config'ed cgfour0 at 0xFE800000)

If course, there is still the problem of not being able to address the DAC,
so the colors are all hosed, but at least this is a start.

This brings me to two more questions....

A) Any idea what AMD DAC is in the "Type A" cg4?  I figure I'll tear open
my machine and take a look around and see if I see anything with AMD on

B) Where would one go about finding info on how to twiddle the AMD DAC?

AMD's website and 'fax back' technical info is only for current products it
looks like.  Any idea what to look for in the library?  Did Sun ever
the information to manuals/books publishers?  Is there some standard
series of manuals I should try and dig up for this info?
  //  Scott Ellis   //   //   //
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