Re: Accelerating the Disk II?

[mkelsey@spam.eecs.wsu.edu]

In article <6eora4$17m$1@cletus.bright.net>,
	"Rick Kerman" <rkerman@mail.bright.net> writes:
> mkelsey@spam.eecs.wsu.edu wrote in message
> <6encp0$h1p$2@leopard.it.wsu.edu>...
> 
> DOS 3.3 pretty much reads one sector at a time, and ProDOS
> pretty much reads one logical block at a time (two sectors).
> You could certainly write your own code to load sectors into
> memory in a more efficient way, maybe even entire tracks at
> a time.  There are also encoding schemes that can be read
> much faster than the standard 6x2.  If memory serves, 4x4
> can be read in real time with 1:1 sector interleave, and has
> been used by game and utility publishers to make fast-boot
> disks.  The books Beneath Apple DOS and Beneath Apple
> ProDOS are good places to start (if you can find copies).

I have Beneath Apple ProDOS and there is no mention of an actual
"hardware acceleration."  However, I think you are correct with 4x4 
encoding and I believe Serpentine used quarter-tracks and 4x4 encoding.
I'm not certain, but I find it hard to believe that Wings of Fury would 
have had support for so many disk encoding schemes (Go Roland!)
but then again, Serpentine and SeaFox were both put out by Br0derbund
and both used the same scheme.  Similarly so were Wings of Fury, Airheart
and Prince of Persia. 
 
	-/\/\ichael-

replyto: mkelsey at eecs.wsu.edu