On Sun, 3 Feb 2008 08:21:34 -0500 "Shmuel Metz (Seymour J.)" <[EMAIL PROTECTED]> wrote:
:>Long ago in a galaxy far away, IBM introduced the concept of resumeable :>instructions; an interrupt could occur in the middle of the instruction :>execution and the instruction would continue properly after a normal :>dispatch. It appears that CLCL and MVCL were not only the first such long :>instructions but also the last. Subsequent long instructions have required :>testing the condition code to see whether the instruction had been :>interrupted in media res. Superficially that seems like extraneous :>overhead. Can anybody cast any light on why IBM went that way? I think it is because these storage to storage operations can take so long to execute, so long that the CPU would assume a problem and go into a check-stop. -- Binyamin Dissen <[EMAIL PROTECTED]> http://www.dissensoftware.com Director, Dissen Software, Bar & Grill - Israel Should you use the mailblocks package and expect a response from me, you should preauthorize the dissensoftware.com domain. I very rarely bother responding to challenge/response systems, especially those from irresponsible companies. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
