On Friday, 05/20/2011 at 09:00 EDT, Tom Huegel <tehue...@gmail.com> wrote: > Can anyone point me to a doc that has the format of ECKD Home Address (HA) and > Record 0 (R0) records?
It's odd that the most recent programming reference for ECKD DASD (IBM ESS S/390 Command Reference, SC26-7298) does not describe the format of the HA except to say that it is 5 bytes. Dragging out an old 3880 book, READ HOME ADDRESS transfers "the flag, cylinder, and head bytes of the home address area." I'm assuming that's of the form FCCHH. I only see a description of flag byte bits 6-7='10': Next track defective. In that same 3880 book, READ SPECIAL HOME ADDRESS transfers "the skip control bytes, segment number, physical address bytes, flag, and identifier bytes (CCHH) of the home address area" with no further description. I'm guessing that detailed HA content is part of the proprietary disk architecture, but you'd have to raise a problem to your storage vendor to find out. R0 doesn't have any special format except that it is 8 bytes with KL=0. The most r Alan Altmark z/VM and Linux on System z Consultant IBM System Lab Services and Training ibm.com/systems/services/labservices office: 607.429.3323 mobile; 607.321.7556 alan_altm...@us.ibm.com IBM Endicott
