MVS TOOLS AND TRICKS OF THE TRADE MAY 2003 Sam Golob MVS Systems Programmer P.O. Box 906 Tallman, New York 10982 Sam Golob is a Senior Systems Programmer. He also participates in library tours and book signings with his wife, author Courtney Taylor. Sam can be contacted at sbgolob@cbttape.org. Information about the CBT MVS Tapes can be found on the web, at http://www.cbttape.org. THE CBT OVERFLOW TAPE Today I'd like to say a few words about a lesser-known part of the CBT MVS collection of software, which I think people should notice. Most folks will look at the very large "regular" CBT Tape collection itself. But quietly, there is another piece of the CBT Tape collection that has been picking up more and more importance. This is the "CBT Overflow Tape". I'd like to start, by supplying some of its history and trivia. As is implied by its name, the CBT Overflow Tape was originally created in 1996 because the regular CBT Tape got too big. Even today, the CBT Tape collection is actually on tape. It is on honest to goodness tape. Most people access the CBT collection from its web site, but the individual "CBT" and "Overflow" subdirectories (and the CBT249 subdirectory) each actually contains the complete contents of one physical tape. So how big is a tape? Originally it was a 2400 foot 6250 bpi reel. Then, as more people were in possession of cartridge drives, it became an uncompressed 3480 tape cartridge, which contains more data than a 2400 foot reel tape does (maybe the equivalent of about 3000 feet of tape at 6250 bpi). Finally, as the contributions accumulated and the uncompressed cartridge threatened to overflow, we took an informal survey and decided that enough people had 3480 IDRC drives, so we could distribute the CBT collection in that format. That's the type of tape which we use today. One 3480 IDRC cartridge can hold (depending on data type) perhaps the equivalent of about 5000 feet of 6250 bpi tape. As of right now, the regular CBT Tape has almost this amount of data, and the CBT Overflow Tape contains about 4200 feet of data. So they're both pretty robust. By the way, if your shop didn't have an IDRC-capable tape drive, we thought of that too. We developed a variant of the COPYFILE program from CBT Tape File 316, called COPYNLNL, which can be used to copy, say, the first 300 files from a big NL tape onto one reel, and the rest of its files onto a second reel. Thus, for the shops that needed it, we (or you) could conveniently divide a CBT Tape into two or more convenient parts, to either 2400 foot reels, or to 3480 uncompressed cartridges. One might think that the CBT Overflow Tape largely contains old code, so it should be largely ignored, especially since the "regular CBT Tape" itself is so big and formidable-looking. Well, times are changing. And there actually is a lot of new code on the Overflow Tape too, as the CBT Overflow Tape is beginning to assume a new role. For example, we just received a very large contribution from Fritz Alber called HICS. HICS is an HSM/SMS front-end and DCOLLECT tool, that potentially has great value to assist storage administrators. HICS also happens to contain a very large amount of data, comprising over 535000 80-byte card images, making it the single largest file on all of the CBT Tape collections. Administratively, we couldn't put one 273-foot (at 6250 bpi) file on the regular CBT Tape. So we put it on the CBT Overflow Tape as File 300 there. HICS is new code, and it stlll has a place on the CBT "Overflow" Tape. That should give you an idea of the new role which the CBT Overflow Tape is beginning to play. ACCESSIBILITY OF THE OVERFLOW TAPE MATERIALS You can get to all the CBT Tape materials from its web site, www.cbttape.org, which is also accessible from the www.naspa.com web site. As all the CBT Tape materials are publicly available, you do not need to be a "member of anything" or to have a password, to access CBT Tape materials. That was the premise from the beginning of the collection when it was a tape--it belongs to the public. Once on the web site home page, you can click on "CBT", which will get you to the complete "regular CBT Tape" collection, and you can click on "Overflow", which will give you access to the complete CBT Overflow Tape. I'd like to say a word about Updates. Many files on the CBT Tape collection are updated quite frequently. On the regular CBT Tape, we've recently been processing file updates or additions at the rate of about 20 files per month. That's about the rate that updates have recently been coming in. The CBT Overflow Tape files are updated less frequently, but because the regular CBT Tape is now almost full, and we are starting to shuffle big (but still current) files to the Overflow Tape, the Overflow Tape is now being updated quite often as well. Where do the most currently up-to-date files get stored? They are accessible from the CBT Tape web site on the "Updates" page. And the updated files to the CBT Overflow Tape can now be found on the Updates page too. Just look immediately below the updates to the regular CBT Tape, and you'll see what's new on the Overflow Tape as well. To those of you who are not familiar, I'll explain why we have an Updates page on the CBT Tape web site. Whenever we feel it is necessary, a new version of the regular CBT Tape, or the CBT Overflow Tape, is cut. This means that all the files on the tape which have not been changed, will be copied to the new version, while the new versions of the files that have been changed, will be substituted for the old versions of those file numbers, and merged into the new cut of the CBT Tape. In addition, a new version of the File 001 documentation of the entire tape contents, and a new version of the File 003 "tape to disk JCL" will always be supplied. What about in-between the CBT (and Overflow) tape version cuts? Sometimes, a useful program or software package has been contributed, and we want to make it available to the public right away. So all the newest stuff, in between the tape version cuts, goes on the web site's Updates page, and it is immediately avalable to be downloaded. That procedure also takes the pressure off me, to be constantly making new version cuts of the CBT Tapes. Any updates are "pretty instantly" available, and they don't have to be made a part of the current "official tape" in order for people to use them. WHAT'S ON THE CBT OVERFLOW TAPE? Basically, there are three types of things there. First, as the name implies, there are overflow materials that are either too big, or not current enough, for the regular CBT Tape. So those materials will occupy files on the CBT Overflow Tape. I might add the observation that files that are "not current enough" are now widely being used by people who are running old free MVS 3.8 on their Hercules systems. Second, there are large software collections--complete "other tapes" as well, which used to be available as MVS software tapes, but which now are either hard to obtain, or which are not available at all. In this category are SHARE's old MVS tape (called the SPLA MVS Tape or the SHARE MVS Tape), the SHARE PL/I Tape, European and Asian G.U.I.D.E. tapes, the last version of the Los Angeles MVS Users Group Tape, and others. There is even an ISPF Tape that was going to be distributed by the SHARE ISPF group, but which never got off the ground because of the "depression of 91", when a lot of people lost their SHARE commitments from employers. That collection is called the "ISPF Smoke and Mirrors Tape". I would like to add, that if you are using a program from one of those old tape collections and you have updates to contribute, you should email them to me, so I can update them on the CBT Overflow Tape and make them available. Third, I like to save old versions of code on the Overflow Tape. For example, Ed Jaffe just made some good updates to the TSSO package (regular CBT Tape File 404), so TSSO will run on z/OS and OS/390. (See last month's column for the details.) For people who have older systems though (and we have to worry about them too), we have to keep the previous versions of TSSO. For example, if you're running an MVS that's older than ESA 4.2, you can't run Ed Jaffe's TSSO from File 404. So you have to go to the Overflow Tape File 250, where you'll find the previous TSSO version preserved intact. OVERFLOW TAPE VERSION NUMBERS As most of you know, the regular CBT Tape has consecutive version numbers. For example, as of this writing, the current CBT Tape version is 458, and we're currently accumulating the updates for version 459. You can find on these updates we're accumulating, on the Updates page of the CBT web site. However, we decided that since the updates to the CBT Overflow Tape are more sporadic, it would make sense to keep its version numbers roughly the same as the then-current regular CBT Tape. For example, recent version numbers of CBT Overflow Tapes have been 421, 422, 428, 447, 455, 458, and 459, with all the in-between numbers having been skipped. I just want to clarify that situation so the skipped version numbers will not confuse you. PLEASE EXPLORE I'm writing this month, to make you more aware of the "other parts" of the CBT Tape collection, where it is very likely that you might find MVS software programs useful to you. In addition, there are even older versions of CBT Tapes available at the CBT web site, for example, CBT249, which is 1985-vintage stuff that could be helpful, especially for the growing number of people who are running old MVS systems under Hercules. If you want to look at really ancient MVS stuff, there are complete AWS-format versions of CBT versions 072, 103, and 129. You can use the VTT2TAPE program from CBT File 533 to cut real tapes or cartridges from AWS-format tapes (see the instructions on File 533 for how to do it). Otherwise, if you have a P/390 or a Hercules system, you can read these files directly as though they were tapes. It is not "madness" or "packrat-ism" that encourages us to keep old versions of the CBT Tapes. Arnold Casinghino, who was the first proprietor of the CBT Tape collection (I am the second), used to delete files regularly from the tape. When Arnie felt that the tape was filling up, he'd delete a bunch of files, as he did immediately after version 249. The result of this, is that if some installation was using one of the programs that got deleted, they then wouldn't have easy access to the original version of the source code, unless they had saved it themselves. Often, they would only have a load module, which might have stopped working on a newer MVS version. As proprietor of the CBT collection since 1990, I have gotten numerous requests for source code to programs, only to have found them on very old CBT Tape versions. So as a safeguard to archive the original versions of old programs, we make it a practice to keep as much of the old sources available as we can, by archiving these old CBT Tapes at the web site. One final note. What does "CBT" stand for? It originally stood for the Connecticut Bank and Trust Company, where Arnold Casinghino (the tape's proprietor) worked. After that bank folded and I had to take over the collection, we were wondering whether to rename it. Since everybody already knew the "CBT" name, we decided to keep it and tell everyone that it does not stand for anything in particular. Privately, we joked that it stands for "Casinghino's Big Tape". It has absolutely nothing to do with "computer based training". I hope that you have enjoyed this month's column, which is a kind of "break in the action". But I'd make a good bet that there'll be dozens of shops around the world who will get very big mileage out of some of the materials on the CBT Overflow Tape.