Yes, I'm writing to 3490E cartridges, afaik. I didn't know that they were being discontinued. I'm going to have to find documentation on that.
The requirements are easy. We ship tapes to a hardware duplication service. That means they mount our tape on one side, and a stack of tapes on the other side, and push a button. Thus, the data on the "source" tape must be under the "guaranteed tape length", otherwise some of the target tapes won't be long enough. So, I can have multi-volume datasets, BUT, the portion of each file must be under the guaranteed minimum length. What our other office does is this: They write files to tape. When they hit a file that causes a tape switch, they back off, rerun the job with one less file, and start another tape with that file. Very crude. I want a better way. I want to be able to write X number of IDRC compressed (bytes/blocks) to a tape, and know for a fact that I am up to the point of guaranteed tape length, and then switch tapes. On a 3480 without IDRC compression, it's easy. I write 8,139 blocks if 24,576 bytes. Then I switch tapes. On a drive with compression, it's not that easy. And I don't like the way my other shop does it. It's hokey, manual and error prone. David Logan -----Original Message----- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Mike Baldwin Sent: Monday, February 04, 2008 10:21 AM To: [email protected] Subject: Re: How to find "current tape length" programatically On Fri, 1 Feb 2008 07:09:04 -0700, David Logan <[EMAIL PROTECTED]> wrote: >I'll start hunting down the block ID value in the 3490 commands today. I >think I'm going to have to issue my own EXCPs though. Hi David, The Read Block ID command (x'22') is documented in IBM 3490E Hardware Reference, e.g. GA32-0219. If you wish to avoid EXCP, you might be able to use the NOTE macro with TYPE=ABS operand. See z/OS DFSMS Macro Instructions for Data Sets, SC26- 7408. I wonder about your requirements though. - Are you writing to real 3490E cartridges? The same ones that I believe will no longer be manufactured in only a few weeks from now? (If so, I know where there are 10,000 still shrink-wrapped on a raised floor...let me know!) - Isn't tape duplication that "cannot have multi-file tapes" (or did you mean multi-volume) of limited value? I respectfully disagree with Mr. Witt that this is easier with 3590 and above, because AFAIK you must first obtain a licence from IBM for 3590 S/390 Hardware Interface Information, or reverse engineer the "new" commands. If you already have the licence, then yes it's easier. (I suppose someone could accidentally give you the information, but that doesn't happen). Regards, Mike Baldwin Cartagena Software Ltd. www.cartagena.com ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
