From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM autolearn=unavailable autolearn_force=no version=3.4.4 X-Received: by 10.157.48.28 with SMTP id d28mr18007875otc.45.1471907691206; Mon, 22 Aug 2016 16:14:51 -0700 (PDT) X-Received: by 10.157.41.230 with SMTP id g35mr1270640otd.19.1471907691175; Mon, 22 Aug 2016 16:14:51 -0700 (PDT) Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!news.eternal-september.org!feeder.eternal-september.org!news.glorb.com!f6no12156176ith.0!news-out.google.com!d130ni43788ith.0!nntp.google.com!f6no12130541ith.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Mon, 22 Aug 2016 16:14:50 -0700 (PDT) In-Reply-To: Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=2601:191:8302:3f70:3d52:1ee3:81e8:b6ec; posting-account=fdRd8woAAADTIlxCu9FgvDrUK4wPzvy3 NNTP-Posting-Host: 2601:191:8302:3f70:3d52:1ee3:81e8:b6ec References: <79e591f0-3c3e-42b2-ad1f-3e59a031531e@googlegroups.com> <94756e03-7788-4032-a70b-3a0468fc3af9@googlegroups.com> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: <8014516e-5d21-4215-a00d-75cf12c76182@googlegroups.com> Subject: Re: Could you write a BSD like os in ADA? From: rieachus@comcast.net Injection-Date: Mon, 22 Aug 2016 23:14:51 +0000 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Xref: news.eternal-september.org comp.lang.ada:31506 Date: 2016-08-22T16:14:50-07:00 List-Id: On Monday, August 22, 2016 at 8:11:36 AM UTC-4, Dmitry A. Kazakov wrote: > On 22/08/2016 13:38, J-P. Rosen wrote: > > Le 22/08/2016 =C3=A0 10:14, Dmitry A. Kazakov a =C3=A9crit : > >> But designing a new OS I would consider doing it really new. No I/O, n= o > >> files, only memory mapped persistent properly typed objects. > > Multics? >=20 > I don't think Multics had typed persistent objects, especially=20 > user-defined ones. You cannot stull all possible types into the OS. It=20 > must be open-end. Um, technically, Multics had three types of files. Boot tapes (yes the 1/2= " wide tape on 12" or smaller spools), backup tapes (managed by Multics, if= you deleted something you didn't mean to, go into the backup system and it= should be there) and finally multi-segment files which were a way to combi= ne segments when you needed more than a megabyte. However, to most users a= ll of this was irrelevant. What is really relevant to this group is that Ada would not have existed wi= thout Multics (and e-mail). The Ada language was developed on several Mult= ics machines, and as a result all Ada developers knew the Multics way of th= inking. The most important thing (IMHO) that Ada got from Multics was the = idea that the OS or compiler should do all the work of maintaining a consis= tent source tree. I never got used to linkers, writing make files, etc. (= Multics did not require linking. If you ran an executable, and it called a= nother unit it would dynamically link it in. If it didn't exist? Multics w= ould tell you and allow you to write it, compile it, resume your program an= d it would use the unit you just created.) Why wasn't there an Ada compiler for Multics? At Honeywell Small Systems (= and other names) where I worked we were tracking the development of Ada wit= h a compiler that ran on Multics and generated code for DPS6 and other smal= l systems. The problem was that our compiler was intended as a systems dev= elopment tool. As a result it could ride roughshod over the OS. Not only = did it "know" how to access the OS internals, it was used to develop things= like the e-mail system. All OS internal calls could be made from within A= da/SIL (for systems implementation language). We arranged for Dansk Datamatik to port their compiler to our system, and w= e validated it. Large systems decided to also port the DDC compiler, but t= o GCOS-8, not Multics. I never found out if they finished, but it was year= s late...=20