Subject: Re: PicassoII, Amiga 2000, 040
To: Antti Miettinen <>
From: Steve Paul <>
List: amiga-x
Date: 06/13/1995 01:17:08
On Mon, 12 Jun 1995, Antti Miettinen wrote:

> OK. I think we have a solution for the 2000 & 040 & Picasso II
> problem. What I'm going to propose works at least for 2000 & Zeus &
> Picasso.

Bravo!  After all this time, progress abounds!

> Mighty weird definition for byte swapping. For example 0x3c9+0xfff ==
> 0x13c8. But my Zeus is pretty weird in other ways also - it won't work
> at 28MHz (the clock rate it was shipped with), but works OK at 25MHz
> and also at 33MHz (with extra cooling :)

  Out of curiosity, are you viewing the "actual" register values?  Is
it repeated trial and error or do you have a reliable way of getting 
the values from the debugger to see the register/data contents?

> But anyway - to which addresses should this offset be applied?
> The problem is apparently colormap initialization. For some reason
> VDAC_DATA appears at address base+0x13c8 instead of base+0x3c9. At
> least for writing. I haven't checked reading. The reason why I was
> able to see something was the fact that the framebuffer went to 15/8
> mode.

 Unfortunately, this patch doesn't quite work for the GVP G-FORCE
boards.  I have a feeling that the kludge for GVP will be far more
sinister.  You are indeed on the right track though- both the
vgaw(...., 0xd0) and the VDAC_DATA kludges produce results on the
VDAC_DATA gives a mono/white X that is overlayed and "ghosted" but the 
windows and pointer are visible!   This is an enormous step from the
black screen I'm used to seeing...  I'm using the latest Xamiga24 
server; is this a good server to use for testing?  The latest Xcl
completely locks my machine, whereas Xamiga24 seems very solid.

If any one has any sample test programs or debugging/testing hints, I'd 
love to hear 'em..   Thanks!

Steve Paul,  McCue Systems, Inc.               	                  Unix/VMS/C/C++ 					           SUN/AMIGA/DEC	       "If at first you don't suceed, redefine success."

Note: The opinions expressed here are my own and do not necessarily reflect the
views of my employer.