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Easy compression tool

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    Easy compression tool

    After hitting a few different pages last night trying to find a simple compression tool for CP/M that would also have a compatible DOS/win32 counterpart, I came up short.

    What I'm looking for is something like pkzip where I can create a compressed archive with more than one file in it. The on the CP/M side uncompress from that one file to multiple files.

    I can deal with only a CP/M side tool and just use zx to use it under win32, but I'm looking for simple. Something that allows adding files to an archive as simple as "arc -a archivename *.*" or "unarc archivename".

    The sites I visited had many of them, but there options didn't make sense or they themselves were archived with yet another tool I didn't know about.

    IZarc for modern Windows supports the creation and extraction of files in the old SEA ARC format. Of course, there were also ARC tools available for MS-DOS. Since there are a number of SEA versions for CP/M, that should handle requirements. ARC handles compression with multiple files and it is easy enough. might help on the CP/M side since it has uncompressed UNARC plus a compressed version with complete manual.


      lu for CP/M 8-bit and nulu for 16-bit DOS is a possibility. Later versions of lu incorporate code from SQ and USQ.


        I ended up finding this which seems to work great so far - the latest versions even support deflate so winzip worked for me on the portable setting.


          Be aware--that will not work on an 8080/8085-based system--only Z80. If you're moving files around to other people, that may leave them up the creek. Note also that the code and binaries are distributed in lbr format, so you'll still be using lu or sweep.


            Maybe I misunderstood their website, I think they were saying that the 154 would work on 8080, and that above that required Z80.


              Can you cite that? I don't see it.


                I think you are right. I saw that where it mentioned 1.5-4 was for CP/M and the 1.8-6 was for Z-system and I thought "Z80" for that.


                  SQ and USQ do work on 8080, IIRC. Simple Huffman compression, if my memory serves.


                    I would avoid ZIP on CP/M if I were you. I can't comment on the utility you link to but historically the CP/M utilities that support ZIP were buggy or used the old algorithm.

                    I would second krebizfan and use something based on SEA ARC as it's well supported on CP/M and has been tested over a long time. There are a number of utilities that support it on DOS/WINDOWS - I used to use PKARC which worked well; I think it later became PKPAK.
                    TechTinkering : Website / YouTube (Retro computers, VIC-20, CP/M, Programming)
                    Latest Video: Advanced Use of .LBR Files on CP/M


                      John Elliott's seasip site includes a set of utilities for PMARC, I'm still checking this out myself but they came through as an arc, they unpacked OK. The progs are essentially CP/M, but one of the options creates a self extracting archive and this archive supposedly will extract on either a PC or a CP/M machine. There's another reference to the system recognising actual file sizes under DOS (I assume it works to block sizes under CP/M).

                      The files on John's site are in bits over three separate packets, so it was a bit of a fiddle to get a single complete set. I'm still working on this. Maybe there is a better package somewhere else? What I have now seems to be complete, but I need to test it.

                      Later... Seems that this system is Z80 only, although there's a reference to the fairly minimal code change needed to make it work for 8080.

                      Also, generally, you can create archives under CP/M, and there's a way (using the SFX) to allow the archive to run/extract on a PC, but there's no way to create an archive on a PC and extract under CP/M, which seemed to be one of the original requirements.

                      The system does have some pluses. The ability to concatenate archives, and the ability to use wildcards for multiple archives, so if you've got multiple archives on a drive and you don't know which one has the file you need to extract, then the process will find it for you and extract it.

                      Last edited by GeoffB17; May 13, 2021, 12:01 PM.
                      Vintage Devices: Epson HX-20/TF-20, Amstrad PCW 8256 (with extras), 386 and 486 PCs with 5.25 and 3.5 floppy drives, Pentium 75 with Roland LAPC-I midi card


                        We're actually talking about two different animals here, aren't we? Compression/decompression software and archiving/library software. Sometime occur in the same product, but not always.

                        I used NSWEEP back in the day Description here.


                          I suppose so.

                          In this case, PMARC is compressing, supposedly as well as something like LHA or ARJ, but it is in effect creating an archive file as well. If you WANT just the archive facility, you can turn compression off, which will increase the speed.

                          I mentioned it here because of the compression/decompression. And the fact that OP was seeking some CP/M-PC compatibility and there is at least a bit of that.

                          I've been using NSWP since I had the CP/M machine, but although the SQ facility is useful, it keeps everything as separate files. Still use NWSP and CWEEP on PCs, but they both do funny things on newer machines. Still OK on the 386 I use for the 'tweener' duties!

                          I think I'm staying 'on topic'?

                          Vintage Devices: Epson HX-20/TF-20, Amstrad PCW 8256 (with extras), 386 and 486 PCs with 5.25 and 3.5 floppy drives, Pentium 75 with Roland LAPC-I midi card


                            I am looking for both a compressor/archiver. Which CP/M side tool do you recommend for ARC? PMARC?


                              There are corresponding PC utilities to handle .lbr files, as well as squeezed ones. Check the SIMTEL20 archive.