Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!killer!elg
From: elg@killer.Dallas.TX.US (Eric Green)
Newsgroups: comp.sys.amiga
Subject: Re: Getting 1.5 MB on a standard 880K floppy without compression
Message-ID: <7627@killer.Dallas.TX.US>
Date: 24 Mar 89 03:03:16 GMT
References: <40@microsoft.UUCP>
Organization: The Unix(R) Connection, Dallas, Texas
Lines: 29

in article <40@microsoft.UUCP>, w-colinp@microsoft.UUCP (Colin Plumb) says:
$ cmcmanis@sun.UUCP (Chuck McManis) wrote:
$> In article <3631@sugar.hackercorp.com> (Karl Lehenbauer) writes:
$>> In the Roomers column of the March 1989 issue of Amazing Computing, the
$>> Bandito says that certain game companies are getting 1.5 MB unformatted
$>> on standard 880K floppies.
$>> Can anyone verify if this is true and if so, explain how it works?
$> 
$> [They seem to use RLL.]
$ 
$ RLL isn't quite the answer.  It's doable, but it's more interesting than
$ that...

[interesting discussion of RLL, and compression gettable via that:]

It may very well be that some of these game companies are staffed by
former C-64 hackers, who remember how the 1541, and all old CBM 8-bit
drives store data -- GCR.  So while the Osborn 1 was storing a whole
90K of data on a single-sided single-density disk using MFM, the Apple
II was storing 120K using GCR, and the CBM 8-bitters were storing 160K
using GCR plus variable bit-rates (putting more sectors on the outer
tracks, and fewer sectors on the inner tracks). It was a great
hardware/software hack.
    Going from 880k to 1500k, though, sounds a bit far-fetched... 

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