And GCS because it runs DAT off, too. -----Original Message----- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Alan Ackerman Sent: Saturday, 11 August 2007 3:07 PM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: Guest in 31 or 64 bit?
On Fri, 10 Aug 2007 17:12:00 -0400, Neale Ferguson <[EMAIL PROTECTED]>= wrote: >No it program checks on an attempt to issue the SIGP to put the machine >in 64-bit mode. > >On Fri, 2007-08-10 at 14:08 -0700, Schuh, Richard wrote: >> Can an XC machine run 64-bit? Isn't XC a pseudo mode invented so that >> CMS could access SFS DIRC directories that were in dataspaces? >========================= ========================== ========== ============== I don't think you can run any guest in XC mode besides CMS, but I don't k= now why. Maybe it has to do with turning DAT on? Nothing to do with 64-bit mode. At least, that was my problem #1 when I installed the Marist Linux distri= bution back in early 2000. (The XC mode was hiding in a directory profile.) This was 31-bit Linux, s= ince 64-bit didn't exist yet (at least outside of IBM). I wouldn't call it a pseudo-mode, though. It is as "real" as anything els= e in microcoded hardware is. It is special in that it is designed to allow use of dataspaces (and = access registers) with DAT off. It's just that the only operating system that I know of that runs DAT off= is CMS. Alan(dot)Ackerman(at)Bank of America(dot)com
