Re: Fast GCR decoding?

From: silverdr_at_wfmh.org.pl
Date: Mon, 14 Jan 2013 15:00:14 +0100
Message-Id: <F7C291D1-441A-471B-B18E-ED1D147CEBDD@wfmh.org.pl>
On 2013-01-14, at 12:40, Nicolas Welte wrote:

>> I found one more claim similar to that, possibly coming from a less "controversial" source:
>> 
>> http://www.c64.com/scene_display_interview.php?interview=178
>> 
>> "I de-coded a [w]hole block in real-time during reading and writing. Not first read in the buffer and then de-code."
>> 
>> It comes from a guy who is the author of (faster than Dolphin) Prologic DOS but I still can't see how could this be done.
> 
> Prologic DOS also uses a decoding table approach, but it can speed up the drive CPU to 2MHz. This is done for reading and decoding, of course.

That would explain: around 40-45 cycles take then half of the 1MHz time, which suffice. Yeah - mystery solved..

-- 
SD!
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Received on 2013-01-14 15:00:04

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