From owner-freebsd-questions@freebsd.org Wed Feb 12 07:24:42 2020 Return-Path: Delivered-To: freebsd-questions@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 61E7724F757 for ; Wed, 12 Feb 2020 07:24:42 +0000 (UTC) (envelope-from bennett@sdf.org) Received: from mx.sdf.org (mx.sdf.org [205.166.94.20]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mx.sdf.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 48HWP50CTwz41cy for ; Wed, 12 Feb 2020 07:24:40 +0000 (UTC) (envelope-from bennett@sdf.org) Received: from sdf.org (IDENT:bennett@miku.sdf.org [205.166.94.6]) by mx.sdf.org (8.15.2/8.14.5) with ESMTPS id 01C7OcD1025747 (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256 bits) verified NO); Wed, 12 Feb 2020 07:24:38 GMT Received: (from bennett@localhost) by sdf.org (8.15.2/8.12.8/Submit) id 01C7OcSW005991; Wed, 12 Feb 2020 01:24:38 -0600 (CST) From: Scott Bennett Message-Id: <202002120724.01C7OcSW005991@sdf.org> Date: Wed, 12 Feb 2020 01:24:38 -0600 To: freebsd-questions@freebsd.org Subject: terminology and history (was Re: Re updating BIOS) Cc: "Steve O'Hara-Smith" User-Agent: Heirloom mailx 12.5 6/20/10 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 48HWP50CTwz41cy X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=none (mx1.freebsd.org: domain of bennett@sdf.org has no SPF policy when checking 205.166.94.20) smtp.mailfrom=bennett@sdf.org X-Spamd-Result: default: False [-1.21 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-0.99)[-0.991,0]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; IP_SCORE(-0.29)[ip: (-0.93), ipnet: 205.166.94.0/24(-0.46), asn: 14361(-0.03), country: US(-0.05)]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[sdf.org]; AUTH_NA(1.00)[]; NEURAL_HAM_LONG(-0.83)[-0.827,0]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCPT_COUNT_TWO(0.00)[2]; RCVD_IN_DNSWL_NONE(0.00)[20.94.166.205.list.dnswl.org : 127.0.10.0]; R_SPF_NA(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:14361, ipnet:205.166.94.0/24, country:US]; MID_RHS_MATCH_FROM(0.00)[]; RCVD_TLS_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 12 Feb 2020 07:24:42 -0000 On Sun, 9 Feb 2020 08:41:11 +0000 Steve O'Hara-Smith wrote: >On Sun, 09 Feb 2020 02:09:59 -0600 >Scott Bennett wrote: > >> The first part of the above, mispunctuated pair of sentences is >> correct, but the latter part is not. FreeDOS, like PC-DOS and MSDOS >> before it, is/was not an operating system, but rather a more primitive >> creature known as a monitor system. > > The DOS part of those names is an abbreviation of 'Disc Operating >System' - clearly at the time they were considered operating systems even They may have been considered that by amateurs from the ham radio community or by the ignorant twerps like Bill Gates et al., who closed their eyes, ears, and minds to all that was already well known to people who had been working in the field for years. That Micro$lop has always misnamed things from time to time should come as no surprise to anyone here. Calling a radio a television does not make it a television. >though they started life as near clones of CP/M (Control Program/Monitor). And that was more correctly named, though/because it was *not* named by Micro$lop. >IBM 360 mainframes didn't have virtual memory, processes or any of the Virtual memory support was a very late addition to operating systems. Before that time, all operating systems and monitor systems were real memory systems only. While most System/360 models had no hardware features to enable operating system support for virtual memory, the model 67 had an extra foot or two of cabinetry filled with the Dynamic Address Translation unit and the CPU could run in standard PSW mode or Extended PSW mode. When in EPSW mode, address translation might be enabled or not. DOS/360 and OS/360 were real memory-only systems, but TSS/360 had full virtual memory support with most of the features that later virtual memory systems had. Although offered by Cambridge University, rather than IBM, CP-67/CMS provided virtual machine support. Some installations ran OS/MFT, OS/MVT, or later OS/MFT II in one or more VMs for batch processing and, for interactive users, CMS in users' VMs. All of this was around by the late 1960s. In the mid 1970s, IBM adapted CP-67/CMS for the enhanced System/370 models as VM 370/CMS and began releasing VM versions of its other systems (DOS/VS, OS/VS1 (i.e., virtualized MFT-II), and OS/VS2 SVS, and OS/VS2 MVS). >protections you mentioned, it didn't even have anything that would be "Processes" were called "tasks" in IBM's operating systems. MVT allowed subtasking, the closest analogue of which in UNIX would probably be threads. All System/360 models (except the 20 and perhaps the 25) either had storage protection standard or could be ordered with it as an option, and were supported by DOS/360 and OS/360 if present. I don't know whether TOS/360 provided storage protection support, TSS/360 required storage protection, but that was standard on the 67 (I think on all models 50 and higher, actually). It also used storage protection in a different manner from the other systems because it could effectively handle the original protection functions much better through memory mapping, while the storage keys could help in managing other matters. >recognised as a filesystem today (it had record oriented datasets) - but They used the standard Volume Table of Contents, which was both volume label and file system. (A file system need not provide a nested directory structure. IIRC, VMS also had a single-level file system.) They provided access methods, OS/360 having several more than DOS/360. OS/360 also had a systemwide catalogue of data sets for those that the user(s) told the OS to keep track of in a central location. They provided tape labelling and recognition, which UNIX systems still do not provide.. Although OS/360 could be installed with one of three options (PCP, MFT, or MVT), which determined to what degree the system would be a multiprogramming system, DOS/360 was a partitioned, multiprogramming system, roughly analogous to OS/360 MFT. (MFT only had one job scheduler running and had other scheduling limitations, too.) In later years, MFT was replaced by MFT II, which allowed many more partitions and with job schedulers running in partitions that were large enough. >OS360 was definitely considered an operating system. > > [MS/PC/DR/Free]DOS was a lot more like a mainframe batch operating No, that was my point. They were all like monitor systems (e.g., IBM 1620/1710 Monitor I). They did almost nothing for the user or program except for loading an executable program from a disk drive and accepting a return of control when the application program ended, so that the next program could be loaded and control transferred to it, just like {MS,PC,DR,Free}DOS. That was a big advantage over having to load a standalone loader on a deck of cards preceding every object program deck one wanted to run, but it certainly was inferior to an operating system. >system than a multi-user multi-tasking operating system such as Multics or Some operating systems embodied no concept of distinct users. For example, if one had not set up the use of accounting features in DOS/360 or OS/360, all users were effectively one. With accounting in use the resource usages could be kept separate for, say, billing purposes, but that was basically all. As far as privileges were concerned, a program ran in user (non-privileged) or supervisor (privileged) mode, but again there was no distinction among users. Very little outside of the supervisor itself ever was allowed to run in supervisor mode. (One exception was spooling systems like HASP, ASP, POP, GRASP, etc., which often came with their own SVC routines that made it possible for them to intercept unit- record I/O to be spooled.) >unix, but hijacking the term operating system to mean only the latterm, and I've been using the terms consistently since 1966. Said hijacking of terms was what I was complaining about. UNIX was very much a latecomer. There were many monitor and operating systems before its first appearance on the scene. Every manufacturer offered its own proprietary system(s). UNIX also was a real memory operating system for many years until after the VAX-11 models were released a decade or more after the 360/67 and at least three years after the 370s appeared that had hardware to enable virtual memory features of operating systems. (It is worth recalling here that VAX-11 stood for Virtual Address Extensions [to the PDP]-11.) >that only with hardware supported isolation mechanisms is revisionist. I >recall working on a unix(ish) system in the late 1980s that didn't have >hardware memory mapping or protection, or even fsck which made recovering >from (the frequent) crashes rather tedious (icheck, ncheck ...). ...which some filesystems did not/do not need. :-) > You have it backwards. Erasing prior computing history would appear to be "revisionist". You're commenting about a time two decades after the appearance of virtual memory features becoming available in both hardware and software, so I don't know what your point here is supposed to be. Furthermore, one of the TSS/360 developers once described to me how they were testing that system in a software simulator of the model 67 on a model 40 a year or two before the 67 hardware was available and working correctly. Note, too, that the VAXes, when they finally appeared, had a design flaw in that they had no reference bits to tell when pages had been accessed for reads, so the CSRG had to simulate reference bits in the kernel. That was kind of inefficient in comparison to reference bits set by the hardware, but far better than not keeping track at all. Why DEC made such a mistake after better examples had been on the market for a good decade I do not know. Scott Bennett, Comm. ASMELG, CFIAG ********************************************************************** * Internet: bennett at sdf.org *xor* bennett at freeshell.org * *--------------------------------------------------------------------* * "A well regulated and disciplined militia, is at all times a good * * objection to the introduction of that bane of all free governments * * -- a standing army." * * -- Gov. John Hancock, New York Journal, 28 January 1790 * **********************************************************************