Newsgroups: comp.sys.cbm
Path: utzoo!utgpu!jarvis.csri.toronto.edu!godzilla.eecg.toronto.edu!leblanc
From: leblanc@eecg.toronto.edu (Marcel LeBlanc)
Subject: Re: turbodisk and IEEE
Message-ID: <89Feb14.155723est.2717@godzilla.eecg.toronto.edu>
Summary: Non-standard formats can give much better speed WITH 1541
Keywords: turbo, non-standard sectors
Organization: EECG, University of Toronto
References: <8902130828.AA09474@MATH.Tau.Ac.IL>
Date: Tue, 14 Feb 89 13:45:50 EST

In article <8902130828.AA09474@MATH.Tau.Ac.IL> <finkel%TAURUS.BITNET@CUNYVM.CUNY.EDU> writes:
>There has been lately a talk about IEEE drives, and their owner's dislike
>of turbo disk programs.
>
>Well, I have written a turbo program for 8050/8250/SFD1001. It uses all 3
>processors ( 2 in the drive, 1 in the C64 ) so it can easily read a full
>track at a time with zero interleave. The program reads the disk using a
>nonstandard file format ( that coexist on the same disk with normal PRG/SEQ
>file ) that uses 256 data bytes per block and continous block allocation on
>the disk. I have a special copy program that prepares such disks. The program
>runs on special IEEE cards manufactured by the company on which I work. (these
>are actually network cards. up to 20 C64's can share the same IEEE drvice ).
>Speed is much faster than anything possible with any C64.. I think it's faster
		^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not true!
>than the C128 burst mode. I also have a C128 version of the program.

It should be faster than the C128 burst mode, because of the greatly reduced
overhead required in decoding non-standard sectors!  This isn't something
unique to IEEE drives, of course.  The _STANDARD_ 1541 fast loader on Super
Snapshot V4 is FASTER than a 1571/C128 in burst mode (12-15x speedup), and
about the same speed as a 1581/C128 in burst mode.  Supplied on the utility
disk, is a translator program which converts to Turbo 25 format.  This is a
non-standard format such as the one you described.  As the name implies, it
achieves 20-25x times speedup over standard 1541.  This is for the C64, and
is MUCH faster that C128 burst load.

Marcel A. LeBlanc	  | University of Toronto -- Toronto, Canada
leblanc@eecg.toronto.edu  | also: LMS Technologies Ltd, Fredericton, NB, Canada
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