Subject: Colour X server for AGA/ECS
To: None <amiga-x@NetBSD.ORG>
From: Gary Henderson <>
List: amiga-x
Date: 01/27/1995 15:41:56

I'm working on a colour X server for X11R6. I've ported X servers to other
hardware platforms before but don't know a great deal about the amiga custom
hardware. In my quest to get the thing running at reasonable speeds when
using deep displays, I have a few questions:

i)   Is it worth investing any effort in trying to use the blitter or can 68030
     perform the same area copying/filling operations faster ?

ii)  Does the blotter only operate on a single plane at a time, so to copy
     an 8 bit deep image around on the screen the blitter copy operation would
     have to be performed 8 times ?

iii) Is anyone working on a device driver for the blitter ?

iv)  Server performance can be boosted somewhat by using a sprite for the mouse
     pointer rather than using the server's internal software pointer code. Is 
     there currently any way to get a sprite on the screen and move it around
     from a process or is a new device driver required? Would a kernel-loadable
     do the trick, and if so, anyone volunteering to write one ?

     I thought trying to mmap the sprite control registers into server address
     space but a forest fire of flames would ensue if anyone else saw the code !

v)   The X protocol requests GetImage and PutImage might have to convert from
     chunky to planar or planar to chunky images; does anyone know of a fast
     software-only alogrithm to convert from one to the other ? I've written one
     already but its not very fast.