From your tape editors: In order to be able to distribute the SIG tapes using the tree mechanism, we view it as desirable to try to limit the size of the combined collection to one reel of tape at 6250 BPI. Since the amount of material submitted is too large to do this any other way, we have preferred to use data compression programs to compress the submissions in places, rather than having to remove items from the distribution arbitrarily. The tools used are furnished in the .tools subdirectory of the index directory for the tape collection (in the Fall '91 case, that would be [91BVAXLT.TOOLS]). To simplify extraction, a few conventions are adopted to specify how to decompress: file.ext_LZW Compressed with LZCOMP, decompress with LZDCMP file.ext_Z or file.ext-Z Decompress with COMPRESS -D (in the second case, rename to file.ext_z). Note that compress deletes the compressed input file if it succeeds, so copy if you want the original compressed file also. file.ext-gz (or some file.ext-z) - Decompress with GUNZIP (gunzip file to decompress.) file.TAZ Decompress with COMPRESS -D as above after rename to file.tar_z; then use a tar format reader to pull the tar file apart. (Tarread23a will do nicely. So will VMSTAR.) file.TAR_LZW Handle exactly as file.taz. These files have generally been produced on unix systems and the most compatible decompressor is Gnu COMPRESS here. file.ZOO Decompress with ZOO. Zoo will be used as the default compress/decompress utility because it allows decompression of selected items in a ZOO archive and directories of the archive without decompressing first. file.LZH Decompress with LHARC. LHARC compresses better than ZOO and so is used in some places instead of ZOO. lharc l file.lzh gives a directory of the file, while lharc e file.lzh pulls the files out of a lharc archive. file.ZIP Decompress with UNZIP. ZIP compresses comparably with ZOO's high-efficiency mode or LHARC, but saves VMS file attributes so is the preferred utility as of Fall 1992 (first tape after the ZIP that preserves VMS attributes was introduced). file.bck_mmmmm_Z Compressed with COMPRESS, decompress with Compress -d. Files named like this are Backup savesets with block size mmmmm. Thus if one encounters Emacs.bck_4096_Z, one must do the following: $ compress -d Emacs.bck_4096 $ file/record=4096/type=fixed/attr=noimpliedcc Emacs.bck_4096 Emacs.bck_4096 is now a valid Backup saveset and can be pulled apart with VMS Backup. This is done because LZCOMP file attribute encoding changes in VMS 5.4 so that files compressed with LZCOMP unde VMS 5.4 cannot be decompressed under VMS 5.3 and earlier without attributes getting messed up at least. The Compress code is robust and portable and not subject to these problems, so this solution will allow us to compress savesets in a way which can be used across platforms and OSs. Because some files are compressed for use on other systems with ZOO or LHARC, these will be named file.zoo_something or file.lzh_something. These are .zoo or .lzh files but normally will be used on other systems and will be left compressed generally. Ditto file.zip_something. Note that some files are compressed as received; these are not touched by the tapecopy people. Thus, a file *.bck_z or *.bck_lz or so on may be compressed by either compress or lzcomp. Sometimes custom tools are used; the files in the [.news60] directory on the 91A tapes for example need to be decompressed with the DECOMPRESS.EXE in the directory with the compressed files. The VMSnet archives files are mainly compressed with LZCOMP and must be decompressed with LZDCMP. The LZDCMP tool (as well as many others) is included in the [.tools] subdirectory of this index area. The tapecopy process this time has used only three compress tools, ZIP, ZOO and COMPRESS, since the new high-efficiency mode of ZOO is at least as good as LHARC. The DECOMPRESS_ALL.COM file nevertheless will do decompression on some of the LZCOMP - compressed files. It will not however erase the originals of these files; nor will it erase ZOO files. It is possible some ZOO files intended for non-VMS systems may have slipped by. If one of these does not decompress correctly try using the command "FILE/TYPE=LFSTREAM FILE.ZOO" command on it. These files should have the carriage control attribute reset prior to trying to transfer them to other systems. Note: ZOO files destined for VMS systems will be set to stream_lf here so VMS ZOO will decompose them properly. ZOO files for programs for other machines will generally be set to fixed 512 byte records for simpler file transfer. The FILE utility (on these tapes) can be used to convert these. Generally .ZOO or .LZH files for VMS will be in stream_lf form, and .ZOO or .LZH files not in stream_lf form are for some other platform. We will attempt to rename all such to .ZOO_something or .LZH_something, but a few may slip by. Future Help: When submitting material, please avoid redundant files. Compress your libraries (especially with /DATA=REDUCE), omit listing or map files, compile without debug unless you MUST have DEBUG there for some reason. Don't bother submitting object files if macro source is supplied, or Runoff output where the input is supplied, as examples. Also, submit programs only when they've changed since you last submitted them. Repetition of old stuff does none of us much good. Versions of someone else's old stuff that you fixed and/or made less crufty are most welcome though. If you can supply ONE file named AAAREADME.TXT in the top level of the directory tree you use (others named something else) it will speed the tape creation process. Finally, PLEASE try not to use directory trees deeper than about 4 levels. Deeper trees cause errors during mastering (where some extra levels are introduced to keep submissions straight as a step in mastering) and can make reproduction of the final tape harder. If you can exclude extra directory levels from your submission, this will be helpful. Thank you. Glenn C. Everhart VAX SIG tapecopy coordinator Note: The file DECOMPRESS_ALL.COM is a template which can be used (AFTER edit please) to decompress the saved material on the distribution. It is located in this directory. The decompress_all.com file deletes files as they are decompressed. Be sure you have a copy of the material before using this, in case anything has errors.