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 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,29f36805b9a20fe8 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-04-05 11:38:10 PST Path: supernews.google.com!sn-xit-03!supernews.com!newsfeed.wirehub.nl!news.maxwell.syr.edu!cpk-news-hub1.bbnplanet.com!cambridge1-snf1.gtei.net!news.gtei.net!inmet!not-for-mail From: Tucker Taft Newsgroups: comp.lang.ada Subject: Re: 6-bit characters (was: Re: Streams in Ada) Date: Thu, 05 Apr 2001 14:37:44 -0400 Organization: AverStar (formerly Intermetrics) Burlington, MA USA Message-ID: <3ACCBB78.71C50154@averstar.com> References: <9aa3dd$efb$1@nh.pace.co.uk> <9aab1e$hhm$1@nh.pace.co.uk> <3AC8F892.87B56B74@boeing.com> <3AC9FD54.47CF0136@boeing.com> <87d7atkgrv.fsf@deneb.enyo.de> <9ad479$i5a$1@nh.pace.co.uk> NNTP-Posting-Host: nebula.burl.averstar.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: inmet2.burl.averstar.com 986495864 27451 141.199.8.77 (5 Apr 2001 18:37:44 GMT) X-Complaints-To: usenet@inmet2.burl.averstar.com NNTP-Posting-Date: 5 Apr 2001 18:37:44 GMT X-Mailer: Mozilla 4.75 [en] (X11; U; SunOS 5.7 sun4u) X-Accept-Language: en Xref: supernews.google.com comp.lang.ada:6522 Date: 2001-04-05T18:37:44+00:00 List-Id: Marin David Condic wrote: > ... > I didn't get that impression. Just that "DECsystem-10" grew from "PDP-10" - > that it was mostly a naming issue & not one of any real fundamental > difference. There may be some technical distinction, but it seems of little > consequence. Same processor. Same instruction set. Maybe some evolutionary > differences, but that's true of all significant systems over time. (How long > have you been able to buy a "Ford Thunderbird"?) > > > | PDP-20 n. The most famous computer that never was. {PDP-10} > > | computers running the {{TOPS-10}} operating system were labeled > > | `DECsystem-10' as a way of differentiating them from the PDP-11. > > | Later on, those systems running {TOPS-20} were labeled `DECSYSTEM-20' > > | (the block capitals being the result of a lawsuit brought against DEC > by > > | Singer, which once made a computer called `system-10'), but contrary to > > | popular lore there was never a `PDP-20'; the only difference between > > | a 10 and a 20 was the operating system and the color of the paint. > > | Most (but not all) machines sold to run TOPS-10 were painted `Basil > > | Blue', whereas most TOPS-20 machines were painted `Chinese Red' (often > > | mistakenly called orange). > > As I recall, the University of Chicago had a DECSYSTEM-20 - but I never > actually got to touch it. What I saw of the data on it tended to indicate > that it used the same KL-10 processor as the DECsystem-10. (KA, KI & KL were > the iterations of the processor I remember.) The major difference between the DECSystem-20 and the DECSystem-10 had to do with memory management. The DECSystem-20 had a better virtual memory capability than the '10. Tops-20, the operating system for the '20, was based on the "Tenex" operating system developed by BBN, which also pioneered the fancier virtual memory hardware for the '10/'20 line. TOPS-10 was the inspiration for the original CP/M-80 which grew up (?) into MS-DOS and then Windows. Tenex/Tops-20 was the inspiration for Vax/VMS, and might be called the "CISC" of the operating system world, where Unix/Linux is the "RISC." It is interesting that the Tenex-Vax/VMS thread joined the Tops10-MS-DOS thread in Windows-NT (the worst of RISC and CISC all wrapped up in one baroque mess ;-). > > MDC > -- > Marin David Condic > Senior Software Engineer > Pace Micro Technology Americas www.pacemicro.com > Enabling the digital revolution > e-Mail: marin.condic@pacemicro.com > Web: http://www.mcondic.com/ -- -Tucker Taft stt@avercom.net http://www.averstar.com/~stt/ Chief Technology Officer, AverCom Corporation (A Titan Company) Burlington, MA USA (AverCom was formerly the Commercial Division of AverStar: http://www.averstar.com/services/ebusiness_applications.html)