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From: Crown (all posts)
Date: 1998-07-06
Subject: Re: Turbo emulating
Hi,

>> You might also try to leave the GCR decoding for the Amiga, and just
>> simply transfer the uncoded bitstream over.
>But is it worth? GCR is longer than the decoded bytes. Ok, I know:
>1541 is far slower in decoding, but takes more time at communicating.
It needs around 25% more time on communication. If your decoding routine is faster than this extra 25% time, than it is not worth to do it.
But if the decoding takes more time, than indeed it's worth to do it.
The point is that while the 1541 actually reads the disk, the Plus4
or the Amiga in this case is in an idle state and it doesn't do anything.
If you move the decoding over to the computer side, your disk reading loop will be faster in the 1541, and the decoding can fit very well into that idle time on the computer side...
One more tip, if you are reading a file, than it is faster to trasnfer whole tracks over to the computer (of course out-of order), as transferring individual sectors. After the track is transferred you just sort out the sector links in the computer side...
This was used if I'm right, in Megaload. Also the GCR decoding trick was used in one of the copy or turbo loader progys.

Tibor Biczo / Crown of GOTU

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