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From: dmw3@ur-tut.UUCP (David M Walsh Jr.)
Newsgroups: rec.games.misc,comp.sys.apple
Subject: Re: zork decoding
Message-ID: <436@ur-tut.UUCP>
Date: Fri, 6-Nov-87 14:13:55 EST
Article-I.D.: ur-tut.436
Posted: Fri Nov  6 14:13:55 1987
Date-Received: Sun, 8-Nov-87 16:30:42 EST
References: <2804@batcomputer.tn.cornell.edu> <7639@reed.UUCP> <434@ur-tut.UUCP>
Reply-To: dmw3@tut.cc.rochester.edu.UUCP (David M Walsh Jr.)
Organization: Univ. of Rochester Computing Center
Lines: 27
Keywords: zork,infocom
Xref: mnetor rec.games.misc:1101 comp.sys.apple:3208

In article <434@ur-tut.UUCP> jra1@tut.cc.rochester.edu.UUCP (The Super Abuser) writes:
>
>I get the impression that the basic coding technique is that
>all the words that are used in Zork's descriptions are stored in some mildly
>compressed format on the disk (probably "3-2" packing of characters), and the
>text descriptions are arrays of pointers to the words on disk.
>
>Of course, I've never tested this theory but it seems reasonable.
>

Yes, I think that I've said this before (maybe it was in a direct reply though)
that I am almost positive that they use the 3-2 packing method: 3 chars per
2 bytes.  The only problem here is that we don't know exactly how they mapped
the alphabet.  The 3-2 packing method easily allows 32 characters in your
alphabet, but you have an extra bit to diddle with, and I don't know if they
played with it.

If I have offended anyone or made a mistake I am sorry, but I'm pretty sure
that this info is correct as far as it goes...

If anyone figures out how it truly works (like if they use that extra bit or 
not...) I'd love to hear from you.

Have a nice day


  David Walsh - an old Apple ][ hacker, slowly becoming a Mac hacker