Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!uunet!mcsun!unido!gmdzi!icking From: icking@gmdzi.gmd.de (Werner Icking) Newsgroups: comp.lang.asm370 Subject: Re: why code in 370 Assembler Message-ID: <4615@gmdzi.gmd.de> Date: 25 Apr 91 11:26:41 GMT References: <1991Apr17.120304.16874@mtu.edu> <1612@msa3b.UUCP> <1991Apr23.190810.16593@ux1.cso.uiuc.edu> <1991Apr24.045329.17509@osh3.OSHA.GOV> Organization: GMD, St. Augustin, F.R. Germany Lines: 27 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."