From: colonel@monmouth.com (Conan the Leprechaun) Newsgroups: alt.folklore.computers Subject: The RADIO program Date: 7 Sep 2002 03:51:15 GMT Organization: Kentucky Fried Fox Lines: 63 Message-ID: NNTP-Posting-Host: bg-tc-ppp218.monmouth.com X-Newsreader: trn 4.0-test76 (Apr 2, 2001) Originator: gls@news.monmouth.com (George Sicherman) Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.imp.ch!news.imp.ch!nntp-out.monmouth.com!newspeer.monmouth.com!news.monmouth.com!not-for-mail Xref: chonsp.franklin.ch alt.folklore.computers:116183 Here's an anecdote from the early days of time-sharing. Stop me if you've heard it. While I was a senior at Harvard (1969-1970), the Aiken Computer Center replaced its SDS 940 time-sharing system (the first I had ever used) with an XDS Sigma 7 system. (XDS and SDS were the same company. The name changed because SDS had acquired political connotations, and the Xerox Corporation had acquired Scientific Data Systems.) The first time I used the Sigma's debugger I was perplexed. The numbers had letters in them! After I got used to hexadecimal, I discovered another peculiarity: my program's code began at location B000. What was stored in 0000-AFFF? It turned out to be an image of system memory, write-protected so users couldn't tamper with it. So this computer not only used hex, it used memory mapping. Here was something you didn't learn about by taking college courses! I wrote a FORTRAN program with negative subscripting to scan system memory for interesting data. I soon found some text areas that changed rapidly. One such area appeared to contain my terminal's most recent input and output, stored in a peculiar circular arrangement. What was going on? A few days later I had written a new program, called RADIO, that let a user at a terminal interactively monitor any other terminal. You could monitor input, output, or both. By shifting into command mode (the prompt was "[" overstruck with "]") you could set various options. Since most users used full duplex, it was best to monitor only the output--except while a user was logging in. For security the system did not echo the password, so to watch the password being typed you had to monitor the input buffer. Often while I used RADIO, other users would walk up and watch. Naturally they were curious, so I told them about the program. They started making copies for themselves. One evening, I monitored a user and found that he was monitoring me! I told him to turn off input monitoring, because every character I typed was being duplicated. He did, and we chatted for a while. This was a great novelty! In those days computer manufacturers refused to provide chat software, fearing that the Federal Communications Commission would subject them to laws governing common carriers. (Or so I heard.) Was this the earliest interactive user-to-user communication on a time-sharing system? Of course operators could send messages to users, but those messages were one-way. In due course the Aiken staff found out about RADIO and deleted it, since it was a disaster for user and password security. But the copies persisted, so they ended up scanning the whole file system to find them. After they were gone, we users returned to our former isolation. I never learned whether XDS heard about the problem or responded to it. -:- Why are you watching The washing machine? I love entertainment So long as it's clean. --More Purple Poetry -- Col. G. L. Sicherman colonel@mail.monmouth.com ###### From: jmfbahciv@aol.com Newsgroups: alt.folklore.computers Subject: Re: The RADIO program Date: Sat, 07 Sep 02 12:22:31 GMT Organization: UltraNet Communications, Inc. Lines: 45 Message-ID: References: <3D799AFD.AF890F6A@bell-labs.com> X-Trace: UmFuZG9tSVYHU1lQ3p1EMevCifgUo2n0LSMHIXlfuJWvhLvXnHk2N8zHxP2rXXYO X-Complaints-To: abuse@rcn.com NNTP-Posting-Date: 7 Sep 2002 13:34:52 GMT X-Newsreader: News Xpress Version 1.0 Beta #4 Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!feedme.news.mediaways.net!priapus.visi.com!news-out.visi.com!hermes.visi.com!feed2.news.rcn.net!feed1.news.rcn.net!rcn!207-172-102-142 Xref: chonsp.franklin.ch alt.folklore.computers:116167 In article <3D799AFD.AF890F6A@bell-labs.com>, Dennis Ritchie wrote: >Conan the Leprechaun wrote: >> >> Here's an anecdote from the early days of time-sharing. Stop me if >> you've heard it. > ... >and more interesting material about a (somewhat surreptitious) >implementation of inter-user communication on the [XS]DS 940. > >> >> Was this the earliest interactive user-to-user communication >> on a time-sharing system? Of course operators could >>send messages to users, >> but those messages were one-way. > >Just down the road, CTSS had the "write" command in its >ancestor of the Multics, then Unix shell. The man page >describing it is dated 9/66, but it probably goes back >further than that. It used "official" mechanisms, that is, the >system calls to send messages to terminals other than >your own were documented, as were the "allow" and "forbid" >commands to control when you could get them. > >I don't recall a multi-user version (as in chat) as >a user-level program, but the system certainly made >such a thing possible. There were different ways to write to a terminal, a.k.a. TTY device, in TOPS-10. There was a SEND command. Anybody who had the SPY. UUO privilege could watch a user. Our equivalent to a newsgroup was the PLEASE command which stored commentary in a file for operations' convenience. I just don't recall anybody ever wanting a CHAT feature (we were all in the same room and could yell over the wall (if it existed) at each other. SEND command had an ALL option (needed privs) that would send the following comment to all terminals. It took some programming to exclude PTYs (pseudo-teletypes). /BAH Subtract a hundred and four for e-mail. ###### From: Dennis Ritchie Newsgroups: alt.folklore.computers Subject: Re: The RADIO program Date: Sat, 07 Sep 2002 06:21:49 +0000 Organization: Bell Labs / Lucent Technologies Lines: 26 Message-ID: <3D799AFD.AF890F6A@bell-labs.com> References: NNTP-Posting-Host: 135.104.65.78 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: fu-berlin.de 1031379071 59226813 135.104.65.78 (16 [156882]) X-Mailer: Mozilla 4.61 [en] (WinNT; U) X-Accept-Language: en Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.imp.ch!news.imp.ch!fu-berlin.de!uni-berlin.de!135.104.65.78!not-for-mail Xref: chonsp.franklin.ch alt.folklore.computers:116131 Conan the Leprechaun wrote: > > Here's an anecdote from the early days of time-sharing. Stop me if > you've heard it. ... and more interesting material about a (somewhat surreptitious) implementation of inter-user communication on the [XS]DS 940. > > Was this the earliest interactive user-to-user communication > on a time-sharing system? Of course operators could send messages to users, > but those messages were one-way. Just down the road, CTSS had the "write" command in its ancestor of the Multics, then Unix shell. The man page describing it is dated 9/66, but it probably goes back further than that. It used "official" mechanisms, that is, the system calls to send messages to terminals other than your own were documented, as were the "allow" and "forbid" commands to control when you could get them. I don't recall a multi-user version (as in chat) as a user-level program, but the system certainly made such a thing possible. Dennis ###### From: "Bob Billing (AKA Uncle Bob)" Newsgroups: alt.folklore.computers Subject: Re: The RADIO program Date: Sat, 07 Sep 2002 14:20:15 +0100 Lines: 26 Message-ID: <3D79FD0F.A948B51A@tnglwood.demon.co.uk> References: <3D799AFD.AF890F6A@bell-labs.com> NNTP-Posting-Host: tnglwood.demon.co.uk Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: news.demon.co.uk 1031410664 13400 158.152.132.30 (7 Sep 2002 14:57:44 GMT) X-Complaints-To: abuse@demon.net NNTP-Posting-Date: Sat, 7 Sep 2002 14:57:44 +0000 (UTC) X-Mailer: Mozilla 4.72 [en] (X11; U; Linux 2.2.14-5.0 i586) X-Accept-Language: en Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news.imp.ch!news.imp.ch!zen.net.uk!peernews.cix.co.uk!shale.ftech.net!news.ftech.net!kibo.news.demon.net!demon!news.demon.co.uk!falstaff.tanglewood!nobody Xref: chonsp.franklin.ch alt.folklore.computers:116214 Dennis Ritchie wrote: > I don't recall a multi-user version (as in chat) as > a user-level program, but the system certainly made > such a thing possible. The sigma range had some frightening security holes. There was a machine in the Engineering lab in Cambridge in the 1970s which was supposed to be used for, among other things, teaching fortran to the undergrads. A chum of mine wrote something that worked in a mind-bogglingly simple way to read the password for any protected file. Basically it tried to access the file with a random password, got blown off with an error then triggered a private crash dumper that printed the area of memory into which the system had read the unencrypted password file. ISTR he got hauled up before his tutor for that one, and we concocted a defence on the lines of "The security is so trivial to defeat that I thought it was intended as a reminder, not a prohibition." His tutor dropped the case against him. -- I am Robert Billing, Christian, inventor, traveller, cook and animal lover, I live near 0:46W 51:22N. http://www.tnglwood.demon.co.uk/ "It burned me from within. It quickened; I was with book as a woman is with child." CS Lewis - Till we have faces, Ch 21.