Xref: utzoo comp.sources.d:2044 comp.binaries.ibm.pc.d:139
Path: utzoo!mnetor!uunet!swlabs!omen!caf
From: caf@omen.UUCP (Chuck Forsberg WA7KGX)
Newsgroups: comp.sources.d,comp.binaries.ibm.pc.d
Subject: Re: Standard for file transmission
Message-ID: <679@omen.UUCP>
Date: 5 May 88 23:00:52 GMT
References: <292@cullsj.UUCP> <55@psuhcx.psu.edu> <537@csccat.UUCP>                <296@cullsj.UUCP>
Reply-To: caf@omen.UUCP (Chuck Forsberg WA7KGX)
Organization: Omen Technology Inc, Portland Oregon
Lines: 74
Keywords: protocol compression source

In article <296@cullsj.UUCP> jeff@cullsj.UUCP (Jeffrey C. Fried) writes:
:
:  1) COMPRESS is a text only compression routine.  It will not now, or ever,
:     help in the compression of binary files.
The 13 bit compression in zoo gets about 29% compresseing YAM.EXE.
:  2) ARITH is a more general compression routine using adaptive arithmetic 
:     coding.  It will compress binary files where there is redundancy, but
Please post it!
:  3) The source for ZOO, PKARC, and the others is NOT available.  Therefore
:     we are at the whims of whomever is currently supporting (or not supporting)
:     them.
The sources to ZOO *are* available, in fact it was a copy of ZOO I compiled
for 386 Xenix that I used in the above micro-benchmark.
:  4) COMPRESS works faster and better on text files then the ARC routines
:     because they use 12 bit compression, where 13-bit (and more) are possible
:     under even the PC for COMPRESS (i've tried it on ans AT-clone).
Compress, ARC, PKARC, and ZOO all use forms of LZW compression, derived
from the original Unix compress program.
:  5) On the weak side, there is as yet, no CRC or checksum for any of these,
:     but adding it would be someithing i am willing to take responsibility
:     for should enough people decide they would like to take the approach
:     which i'm currently suggesting.
The lack of a CRC in compress is a serious weakness.  ZRC and ZOO include CRC.
:     Also, there no directory support provided with these tools.  They work
:     on only one file at a time.  This is also correctable since the source
:     is available.
ZOO has excellent directory support - full Unix pathnames are supported.

Again, please post the ARITH program.  It would be most interesting
if the memory requirements are small - like Huffman encoding instead
of LZW.
Newsgroups: comp.sources.d,comp.binaries.ibm.pc.d
Subject: Re: Standard for file transmission
Summary: 
Expires: 
References: <292@cullsj.UUCP> <55@psuhcx.psu.edu> <537@csccat.UUCP>                <296@cullsj.UUCP>
Sender: 
Reply-To: caf@omen.UUCP (Chuck Forsberg WA7KGX)
Followup-To: 
Distribution: 
Organization: Omen Technology Inc, Portland Oregon
Keywords: protocol compression source

In article <296@cullsj.UUCP> jeff@cullsj.UUCP (Jeffrey C. Fried) writes:
:
:  1) COMPRESS is a text only compression routine.  It will not now, or ever,
:     help in the compression of binary files.
The 13 bit compression in zoo gets about 29% compresseing YAM.EXE.
:  2) ARITH is a more general compression routine using adaptive arithmetic 
:     coding.  It will compress binary files where there is redundancy, but
Please post it!
:  3) The source for ZOO, PKARC, and the others is NOT available.  Therefore
:     we are at the whims of whomever is currently supporting (or not supporting)
:     them.
The sources to ZOO *are* available, in fact it was a copy of ZOO I compiled
for 386 Xenix that I used in the above micro-benchmark.
:  4) COMPRESS works faster and better on text files then the ARC routines
:     because they use 12 bit compression, where 13-bit (and more) are possible
:     under even the PC for COMPRESS (i've tried it on ans AT-clone).
Compress, ARC, PKARC, and ZOO all use forms of LZW compression, derived
from the original Unix compress program.
:  5) On the weak side, there is as yet, no CRC or checksum for any of these,
:     but adding it would be someithing i am willing to take responsibility
:     for should enough people decide they would like to take the approach
:     which i'm currently suggesting.
The lack of a CRC in compress is a serious weakness.  ZRC and ZOO include CRC.
:     Also, there no directory support provided with these tools.  They work
:     on only one file at a time.  This is also correctable since the source
:     is available.
ZOO has excellent directory support - full Unix pathnames are supported.

Again, please post the ARITH program.  It would be most interesting
if the memory requirements are small - like Huffman encoding instead
of LZW.