Re: Fast GCR decoding?

From: Spiro Trikaliotis (ml-cbmhackers_at_trikaliotis.net)
Date: 2005-11-08 11:01:04

Hallo Ruud,

* On Tue, Nov 08, 2005 at 10:06:31AM +0100 Baltissen, GJPAA (Ruud) wrote:
 
> > The overhead of transferring more data (320 byte vs. 256 byte) might
> > be less than the time you gain by moving the decoding into the
> > computer.
> 
> IMHO that is just shifting the problem AND loosing time because you
> have to send more data.

Not necessarily. The drive can look for and read the next sector while
the C64 is still decompressing. This way, you can save time.

Furthermore, the C64 can utilize much bigger tables than the floppy can.
This way, decompression can be speed up on the C64 than it is possible
inside of the flppy.

Another, possibly better approach might be to do some work on the floppy
(as much work as there is time before the next track is to be read), and
do the rest in the computer. For example, you might decode bytes 0 - 50
(or so) in the floppy, and the rest in the computer. Anyway, this might
require very much thought about the details.

Regards,
   Spiro.

-- 
Spiro R. Trikaliotis
http://www.trikaliotis.net/
http://cbm4win.sf.net/

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