It's the bar! Only 4KB thick, a big improvement over what I originally called* the bar from x'80000000' through x'FFFFFFFF'. That one however, is now available for certain uses, although I would avoid it for the same reasons it was originally black-listed.
*In no way is this a claim I have naming rights. On Fri, Jun 17, 2016 at 12:27 PM, Walt Farrell <walt.farr...@gmail.com> wrote: > On Fri, 17 Jun 2016 11:21:44 -0400, Jim Mulder <d10j...@us.ibm.com> wrote: > > >> >>For diagnostic purposes, then 4K page at 7FFFF000 is always > >> >>left invalid in z/OS. > >> > > >> >That makes the highest numbered, accessible byte to be at address > >x'7FFFEFFF' > >> > > >> That might be due to a requirement of ANSI C that there always be an > >address > >> algebraically greater than that of any accessible object, for loop > >termination > >> conditions. > > > > Not likely. It has been that way since the first release of MVS/XA, > >circa 1982. That was a time when MVS still ruled with arrogance, and it > >would takes some doses of marketplace reality changes a few years later > >before > >MVS became interested in accommodating C and Unix. > > In any case, "ANSI" C didn't exist until (I think) 1989, though the > standardization effort began in 1983. So the technique is certainly older > than ANSI C, and not related to it. > > -- > Walt > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > -- sas ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
