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From: mcsun!unido!gmdzi!icking@UUNET.UU.NET (Werner Icking)
Newsgroups: comp.lang.asm370
Subject: Re: why code in 370 Assembler
Message-ID: <9104251704.AA13513@ucbvax.Berkeley.EDU>
Date: 25 Apr 91 11:26:41 GMT
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Reply-To: IBM 370 Assembly Programming Discussion List
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chip@osh3.OSHA.GOV (Chip Yamasaki) writes:

>In <1991Apr23.190810.16593@ux1.cso.uiuc.edu> phil@ux1.cso.uiuc.edu (Phil
        Howard KA9WGN) writes:

<>kevin@msa3b.UUCP (Kevin P. Kleinfelter) writes:
[...]
<>You see, the difference between low level and high level, as I think of
<>it anyway, is NOT how much you can do in one instruction, but rather
<>how much control you have over HOW things are done.  C gives you LESS
<>control because you don't get to choose the precise instruction.  Higher
<>languages like Pascal and ADA give you even less control and that lack
<>of control starts to span over into things like data representation itself.

>One question though.  It has been a long time since I took a 370 ALC
>course in school (and I didn't know then either), but does that MVC/MVCL
>instruction resolve to 1 machine code instruction?  If so, then I
>suppose you're right.  If not then you're back to square one.

Yes AND no: MVCL is one machine code instruction for the assembler. But
the machine instruction is interruptible e.g. to handle page-faults and
paging-in the required pages. So it is a low-level language and a high-level
machine? :-)
--
Werner Icking          icking@gmdzi.gmd.de          (+49 2241) 14-2443
Gesellschaft fuer Mathematik und Datenverarbeitung mbH (GMD)
Schloss Birlinghoven, P.O.Box 1240, D-5205 Sankt Augustin 1, FRGermany
                                  "Der Dativ ist dem Genitiv sein Tod."