Date   : Sat, 15 Nov 1986 06:22:00 MST
From   : Keith Petersen <W8SDZ@SIMTEL20.ARPA>
Subject: Compression schemes and no source code

> I had retrieved a copy of <CPM.CCP>conix.lbr and found many of
> the files had .DZC or .CZM extensions.  Can you tell me what
> compression scheme was used to squeeze these files?

> Also, if there is some handy CP/M-80 utility to unsqueeze them,
> could you pass its name along as well?

Yes, there is a program called CRUNCH (and companion UNCRunch) which
does Lempel-Zev-Welch style file compression on CP/M-80.  It is far
more efficient than SQueeze/UnSQueeze which uses the Hoffman
algorithm.  The efficiency of CRUNCH exceeds that of MSDOS`s
ARC512.EXE utility.

[Flame on] - Too bad the authors of LU and NULU never released the
source code.  We **COULD** have had a combined LBR/CRUNCH which would
have been better than MSDOS's ARC files.  Another stifling of software
expansion/development caused by those who will not share the basic
tools we need to keep CP/M alive. [end of flame].

Filename               Type     Bytes   CRC

Directory PD:<CPM.SQUSQ>
CRUNCH20.DAT.1         ASCII     1984  E4B5H <--performance info
CRUNCH22.LBR.1         BINARY   26880  FAB1H <--Z80 crunch/uncrunch
                                                (no source code available)

--Keith