At 7:45 PM -0400 4/5/99, nigel@ind.tansu.com.au wrote:

>	Yes, and that is what the LC475/575 hack in the Booter is for.

I'd forgotten about that booter hack. Perhaps the offset in the video
controller is getting added to
the "hack" base address instead of the actual offset.

>	The video base address on these machines is MMU mapped under
>MacOS (i.e. the one that the Booter normally gets is not the actual
>hardware base address). If the particular kernel that is being booted
>doesn't have the un-mapped base address compiled in to its tables,
>then the hack needs to be set.

Hmmm. Perhaps it might be worth it to investigate the memory controller. I
got some recent info
about the AV memory controller says that there is a bit that controls where
video memory appears.
It's entirely possible a similar bit must be flipped on the LC*75 machines
so video appears at
its physical address. That will allow us to get rid of the booter hack.



_______________________________________________________________________
 Michael Zucca - mrz5149@acm.org - http://www.mdc.net/~mrz5149/
 "I will choose a path that's clear. I will choose Freewill. "
  --Rush, Freewill
_______________________________________________________________________