I'm piecing together various clues. It appears to me that: 1. The UCCB is a defined control block, mapped in several (!) MACLIB members such as CUNBAIDF. 2. Various flags are defined beginning at UCCB+10. 3. Somehow during IPL the system clock has been overlaying UCCB+10 by (presumably) Unicode set up processing. 4. No one noticed all this time because the flag nibble in the timestamp has always, coincidentally, indicated 'Unicode available'. 5. As of the magic moment on December 15, the clock rolls over and reverses the benign bit. Without the fix, Unicode appears to be unavailable more or less forever. Until the bit once again changes back?
I suspect that checks for the timestamp are far rarer than checks for Unicode availability. So the fix is to store the clock somewhere else at IPL (UCCB+20) and ensure that the critical flags are zero. Our PMR indicates what I suspected: a zero value means OK, a one value means not OK. This is analogous to the RACF flag in the CVT. Zero means that RACF is functional while one means that it is not. I have a hilarious war story about how I know that. . . . J.O.Skip Robinson Southern California Edison Company Electric Dragon Team Paddler SHARE MVS Program Co-Manager 626-302-7535 Office 323-715-0595 Mobile [email protected] -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Paul Gilmartin Sent: Thursday, October 15, 2015 6:07 PM To: [email protected] Subject: (External):Re: Unicode services Red alert On 2015-10-15 17:37, J O Skip Robinson wrote: > I think I received the following link internally rather than from IBM-MAIN. > It's a good discussion of the issue. > > http://www-01.ibm.com/support/docview.wss?uid=isg1OA48941 > I'm curious: how (not when) does this problem occur? Is it some OCO doing a TM on the wrong address? I suppose I should infer something from: Problem summary **************************************************************** Correct the code involved to move the timestamp field to allow the Unicode services active indicator to remain valid. -- gil ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
