Path: utzoo!attcan!uunet!lll-winken!lll-lcc!ames!pasteur!ucbvax!pro-carolina.cts.COM!delton
From: delton@pro-carolina.cts.COM (Don Elton)
Newsgroups: comp.sys.apple
Subject: SQ and USQ algorithms
Message-ID: <8805260536.AA05815@crash.cts.com>
Date: 25 May 88 23:35:36 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: pnet01!pro-sol!pro-carolina!delton@nosc.mil
Organization: The Internet
Lines: 13

Someone had posted a note looking for details of the SQueeze and UnSQueeze
algorithms that I ported to ProDOS.  The ORCA/M source code to my stuff is in
the public domain (for SQ and USQ) and is available on Compuserve and some
other places I imagine.  The algorithms were first seen by me at least on CP/M
systems and my 6502 code is basically a hand-compilation of C and Pascal
sources for these utilities under CP/M and/or MS-DOS.  The Apple SQ and USQ
are completely compatible with the CP/M, MS-DOS, and UNIX counterparts.  USQ.C
compiled without errors with APW C but SQ.C wouldn't and I don't have enough C
experience to do the conversion to create ECP16/APW/ORCA compatible EXE files
for SQ and USQ so I just use the 8-bit assembler versions (which are probably
faster than anything the high level compilers could produce anyway).  The SQ
and USQ in BLU were written using my ORCA/M source modified by Floyd Zink to
fit his utility (and to fix a bug which has subsequently been fixed in my
originals).