Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!ucbvax!ALASKA.BITNET!SXRJC
From: SXRJC@ALASKA.BITNET (ROBERT J CONCANNON)
Newsgroups: comp.lang.asm370
Subject: sio & siof
Message-ID: <8912221711.AA27734@brazos.rice.edu>
Date: 22 Dec 89 16:57:19 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: IBM 370 Assembly Programming Discussion List <ASM370%UCF1VM.BITNET@ricevm1.rice.edu>
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on system 370 machines siof causes the cpu to be released for other work
imediately after the channel address work is fetched. sio retains the
cpu until after device selection is completed. for siof the actual i/o
was asynchronous, but if it ultimately fails the overhead can be more
than for sio alone. mvs/xa? i dont know.