You have always been able to write a block of only one byte, or even zero bytes, onto a DASD.
Bill Fairchild Software Developer Rocket Software 275 Grove Street * Newton, MA 02466-2272 * USA Tel: +1.617.614.4503 * Mobile: +1.508.341.1715 Email: bi...@mainstar.com Web: www.rocketsoftware.com -----Original Message----- From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On Behalf Of Rick Fochtman Sent: Monday, August 10, 2009 3:50 PM To: IBM-MAIN@bama.ua.edu Subject: Re: Concatenations and blocksizes ----------------------------<snip>------------------------------ I don't think so, there used to be a minimum BLKSIZE of 18, but that's not detected until you try to open the DSN. No open; no error. IEFBR14 does no open. ---------------------------<unsnip>------------------------------- IIRC, that 18-byte minimum applied only to tape. It was necessary so that the drive could distinguish between inter-block gaps and legitimate blocks. Rick ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu 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 lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html