Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!UCLAMVS.BITNET!CSYSMAS
From: CSYSMAS@UCLAMVS.BITNET (Michael Stein)
Newsgroups: comp.lang.asm370
Subject: CP's DASD Block I/O System Service?
Message-ID: <8907122126.AA08466@jade.berkeley.edu>
Date: 12 Jul 89 19:59:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: IBM 370 Assembly Programming Discussion List <ASM370%UCF1VM.bitnet@jade.berkeley.edu>
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   As an MVS person, I always thought this was a VM list, but
   since I haven't received even one response so far I've decided
   it's just a CMS list...  Anyone have any information on this?
   (last chance on this list).

               - - -

All these questions are about CP's DASD Block I/O System Service.

1. Can multiple Virtual Machines use this service in multi-write
   mode on the same disk at the same time?  I am assuming that
   these VM's are responsible for the interlocking, I just want
   CP to get the I/O done.  (It's not a CMS format disk).

2. Can I use the whole disk (offset = 0)?

3. Can I use negative block numbers if the offset isn't zero?

4. How do I initially format the mini-disk? (CKD/FBA)?
   (This doesn't have to be fancy.  Filling it with 4k blocks
    would be fine as long as all the blocks are there).

5. Is there a non-standard length block near the begining of
   the mini-disk (like a volume label at record 3?)