Subject: views and pagers
To: None <>
From: David Jones <>
List: amiga-dev
Date: 03/24/1994 15:34:42
Is the bitmap for /dev/view implmented via a banked device pager?

I ask this because it seems that the color X displays are backed up by
swap space.  So, whenever you need to access the frame buffer, you page
it in and out of the VM map.

However, the Amiga frame buffer (i.e. chip RAM) can be accessed in its
entirety without paging.  You can map pieces of it anywhere using the MMU,
but you don't actually need to swap anything in or out.


- What can be done to make chip RAM access fast (no paging) yet keep
  compatibility with banked devices, if they exist?
- How does VA->PA translation affect blitting?  With a paged system,
  you usually don't care about contiguity, but the blitter does.

David Jones, M.A.Sc student, Electronics Group (VLSI), University of Toronto
email:, finger for more info/PGP public key