[comp.sys.mac.programmer] block moves to 8-24 card

allenb@comix.cs.uoregon.edu (Allen F. Brookes) (03/23/91)

Does anyone know how to do block moves to an 8-24 or 8-24gc card?  I can
successfully move images to the old style 8-bit video card with block move
but when I try it with the 8-24 card it freezes the machine.  Tech note
288 says that block moves are not supported for nubus slots but since it
works for the standard 8-bit card it seems there should be a way using
the 8-24 card.  It also does not seem to work when I move bytes.  Any
help will be appreciated.

Allen

Greg@AppleLink.Apple.Com (Greg Marriott) (03/23/91)

In article <1991Mar22.174436.2074@cs.uoregon.edu>, allenb@comix.cs.uoregon.edu (Allen F. Brookes) writes:
> 
> Does anyone know how to do block moves to an 8-24 or 8-24gc card?  I can
> successfully move images to the old style 8-bit video card with block move
> but when I try it with the 8-24 card it freezes the machine.  Tech note
> 288 says that block moves are not supported for nubus slots but since it
> works for the standard 8-bit card it seems there should be a way using
> the 8-24 card.  It also does not seem to work when I move bytes.  Any
> help will be appreciated.

Many video cards (especially 24-bit ones) must be accessed in 32-bit mode.
Use SwapMMUMode to change to 32-bit addressing before accessing the frame
buffer on the card and then change back when you're done.  (If you were
in 32-bit mode before, then leave it that way... :)

Greg Marriott
Blue Meanie
Apple Computer, Inc.