2600 Magazine - Volume 1, Number 3 ZOUU March, 1984 — — — == ■ .i^lihlinl HniMiihl^ Iil JMHF l:\IJ.M I’HIM-S, m AthffcwMry pr£Hairali«ifi. KuhuniMk-iii rjiiiL hiu i FD utiaihjJlh . Writ* w Unkn T.JJ. Middk lUind. N V I F«J. FSLN 3 VOLUME ONE NUMBER THREE r THE CONSTITUTION OF A HA CKER With every generation of humane there are certain types- of individual* that emerge. There are (always have been and always wilt be) leaders, followers, general nuisances, etc. And then there are folks who like to play with things and figure out how they work. Before technology came along, there really wasn't all that much for these people to play around with. And certainly there was no way for them to pool their resources except through face-to-face communications. With telephones, of courts all aspects of human life changed. Here was a toy that anyone could play with and get virtually unlimited results. But of course, most people did n’t (and don't) see it that way— rphones are phones and nothing more. You're not supposed to have fun with them. Yet, certain adventuresome type* insisted on having fun with their phones anyway. Tjiey : did all kinds of things they weren't supposed to dg T like figure out the way phones work and interconnect. For the first time, these technological enthusiasts posed a "threat** to technology by reaching out and touching it rather than simply using it without asking any questions. Today there .are Jots of people still having fun with their phones and mi king af I kinds of technological advancements of their own. But the real focus at the moment is on the newest "threat," people who like to experiment and have fun with computers. Not the kind pf fun thcyYe supposed to be having with Pacman^and Mr. Do*, but unauthdriietf fun with other people's computers. Why do they do this? What do these people possibly have to gain by breaking into computer systems and seeing things that don’t really concern them or I hat is of no possible use to them? In the great majority of cases, computer hackers don't gain anything niatefial or financial from their exploration. Add lolhiit the high risk of getting caught and it becomes very hint for the average citizen to understand whpt motivates these people.. Many computer . hobbyists, in fact, are resentful of hackers, consign (bent immature and troublesome. Quite a fc w conDputfcr hu Ucttn boards prohibit certain topics from being discussed, $i)df wtipn they do, hacking is almost always one of them. Tigris, is some justificat ion behind this, since the image of ailcomputcr users can be adversely affected by what t|^ dp. There are pisii the ..tagal people who insist on telling everyone that jbtrica king into ^computer hy phone is just like physically bneatih&iiiioa home or office. Fortunately, that logic seems to feejsbpred by very, few people. In spite of dH/oCf^ greats and ciiticism, though, the hackers arc SOI thpif aci," And public opinion, particularly apjo^g t be young, seems to be in their favor, mostly as a rtsuti of media Coverage There’s, even a ivebkty TV program about hackers called Jhe \Vfu 2 /ffr^4J^eh%ek, this group of a mazing kids has a new adventure. The scripts area bit moronic but interesting nonetheless. In gne episode, the kids (only one of which is a true hacker) find out about an evil person who happens to be stealing Social Security checks. (They discover this by casually logging into his bunk account.) To leach him a lesson, they break into another computer and enter his name as being deceased- In each program, these kids break into at least one new computer. But do they ever get into trouble? Of course not. First of all, they’re only children. And second, they're entering these computers for good reasons, even if they are unauthorized. Now what kind of message is this program conveying? Apparently, it's OK to invade other people’s privacy if your intentions are ultimately "good." It sounds Like something Reagan would gel a kick out of. A genuine hacker breaks into computers for the challenge. He's not out to save the world, nor to destroy it. He is not out to make a profit out of what he's doing. Therefore, it's not fair to categorize him as a criminal and it's just as wrong to say he’s some sort of a savior. Technological enthusiasts operate with the same motivation that a good mountain climber has. Regardless of what may happen to him, a computer hacker wiilaAvfiyj be interested in playing with computers. It’s in his nature. And any laws that are created to “eliminate” hacking simply won't work because of these facts. There will always be people who want to experiment with things and this urge cannot be stifled. Did hacking come to a grinding hall because of the “414" scandal? Or because of the Tclemail raids? No. Judging From the proliferation or computer bulletin boards where hacking is discussed, it's getting bigger than ever. The realistic way for the owners of large computer systems to look at this is to regard backers as necessary security checks. That's right. Necessary because if the hackers weren't the ones to break in, who would be? Let’s assume that hackers had never even tried to break into the Memorial 51 can- Kettering Cancer Center computer. Someone else would have, because the system was practically wide open. And maybe they would have had a reason to get into the system— to do various nasty things. But now, because of what the hackers did, the Sloan- Kettering system is more secure. One could almost say that a person with hacking abilities has an obligation to try and get Into as many different systems as he can. Let's get nationalistic for a moment. If you have the number for a top-secret government computer in Ft, George G. Meade, MD, odds are that the Albanians have it also. Now, would it be better for them to break into the system and find out all kinds of nice things or for you to break in and be discovered, forcing the system to become more protected? And, if you do break in, don't you deserves note of thanks for waking them up? Keep in mind, though, that a computer hacker is undent obligation to turn himselT in or warn operators that their system is easily penetrable. It's the job of the sysops to notice when their computers are being tampered with and if they don't detect you, then that's a second security lapse for them. This is a pragmatic view, however shocking it may seem. In closing; wc should point out to the hackers themselves that there is no need to worry or fret if their methods or secrets are eventually d iscovered. This is only the beginning. Our world is turning into a technological playground. i ALTER J> A I E LOING U1S1AJNLE First of a persistent series — how the companies work and a guide to MCI SWAGIMA. That’s the word that National Public Radio uses to describe Long distance services. It stands for SBS (or Skyline}, Western Union (or Metrofone), Allnet (or Combined Network Services}, GTE Sprint, ITT, MCI, and of course AT&T, And there are many more, each of which will eventually be covered in our pages. Right now though, we’d tike to give you an idea of what these systems arc and how they work. Except for AT&T, ail of the above systems work in a fairly similar manner. (This will be changing very soon and very dramatically under the terms of the Bell divestiture) Each system has its own series of networks* i.e. land-lines, lines leased from AT&T, microwave relays* satellite Links* etc. They each have local city access numbers, although some like Aiinet and MCI have special ways of using a "travel 1 * service by dialing a special number* while Sprint uses a "travelcode” to access nodes outside the subscriber’s city. On others, like Metrofone, you can use the same authorization code from any of their access points. A long distance telephone company consists of four major parts: you have your input — that is, a local access number or a toll-free “£00” number to access the^ystem. When you do this, a device called a “switch 41 answers, giving you the familiar "computer dial tone” When you enter your authorization code and destination number you are routed over their network. The heart of the system is the controlling system, which includes the "switch” This is the computer that checks the authorization code, has provisions for time- of-day restrictions, traveicodes, accounting codes, and the like. They have a few provisions which the longdistance services donY appear to use, such as the infamous “speed number 11 recording which was a favorite of many phone phrtaks (for reasons you’ll soon know if you don’t already). The system checks to see if the Location being dialed is on the network, and acts accordingly. It makes a Log of numbers called, the authorization code, and time usage which is stored on a word processing tape and then read by another system for billing. Some companies charge in one minute increments, although the system has the capability to record time usage in 6 second increments. There are quite a few different systems in use today. A couple of the most common ones art made by Northern Telecommunications, which is based in Dallas, Texas. Another company that sells similar equipment is Rockwell We scorn, MCI allegedly is in the process of buying new switches from them, and they will be installed by Dynacomp Telecommunications, also based in Dallas. Microwave Links Mast of the low cost services, at one point oranother* use microwave antennas to transmit calls, Each microwave . «■ station is Located about 30 miles from each other to make up for the curvature of the earth since microwaves travel in a straight line. Each of these stations has 4 dishes (at least). One dish is used to receive from a previous station and one is used to transmit to that station. The other two dishes do the same thing to the destination station — one receives and one transmits. So if you make a call 3000 miles away* you may wind up going through 100 different microwave stations, many of which you can see next to major highways. This is how the alternate long distance companies manage to charge less than AT&T; they use their own systems. But this is also why, in many instances, (he sound quality is poorer on the alternate services. Remember, a chain of microwave towers is only as strong as its weakest connection. A Look at MCI MCI (Microwave Communications Inc.) was the first new kid on the block, way back in 1967 when the idea of an alternate phone service was almost unheard of and practically illegal. MCI was fust used solely by businesses who wanted to communicate between the cities of Chicago and Cleveland That was it. And even with this amazingly limited system* MCi ran into problems with AT&T, who didn't want anybody trying to do what they did. Lawsuits followed, with MCI e ventually getting a prombe of eventual equal access, to the AT&T network. In fact, MCI’s legal action is considered one of the motivating factors behind the break-up of the Bell monopoly. Now MCI is the biggest of the alternate services (they have well over a million subscriber* at present, having opened their doors to residential customers a mere 5 years ago) and also one of the hardest to penetrate. The system has 5 digit codes that art entered before the (0 digit phone number, a total of 1 5 digits. But these codes only work from one location, making it rather unlikely to find one by guesswork. If you want to use the system from another city, you have to sign up for MCI “credit card" service which costs an additional S5 a month (on top of an initial IS a month charge for the regular service). Here you get a List of 48 phone numbers around the country and a 7 digit code which can be used from any one of them,, Most code seckcre prefer scanning the “credit card” numbers since more numbers work overall. However, a strong argument can often be heard in favor of the 5 digit number* that are located in densely populated areas. like Los Angeles or New York. Naturally* the odds of finding something increase under those circumstances. No Proven Method For Finding Codes MCI, being the oldest of the companies* has learned quite a bit in (hat time. Therefore, no major bugs are still crawling around on their system. Hacker* have many theories on number patterns, of course. For example* numbers like 22212 or 12345 tend not to work. In other words, your guess is as good as our*. As far as what they do when they know a code is being abused, MCI seems to be more interested in changing the code rather than laying a trap, as other companies have been known to do< Of course, this doesn’t mean that they're incapable of doing such a thing. MCE Features The MCI tone sounds like all the others (a hoUowish* medium-pitched, steady tone), but it has its own set of recordings, depending on what you do to it. If you enter an invalid code*, you’ll hear a mechanical female say; "THEE AUTHORIZATION CODE YOU HAVE DIALED IS INVALID TWO ZERO THREE" and then an ESS reorder that trips over itself (listen to it and you’ll understand}. If you dial someplace you're not supposed to call (for whatever reasons), you’ll hear “THEE NUMBER YOU HAVE dialed isnot on the network TWO ZERO THREE" and (he reorder. Each MCI dialup has its own 3 digit identity code and they tend to be simitar the doser together they are. Many businesses are installing MCI “dedicated lines" in {continued on page 4) c I ¥ 718 is coming! I lM PiIlY,- Yfli* ItlTWI The New York Stale Public Service Commission has voted to begin dividing New Yprk City into two area codes on September I to "prevent an impending exhaustion of telephone numbers/' At that timc + the old 2 1 2 area code wilt begin to reach only Manhattan and the Bronx, whereas a brand new area code, 718, wilJ start to work for Brooklyn, Queens, and Staten Island. The whole system becomes mandatory on January 1* 1985, Charles Herndon, a New York Telephone spokesman, said that the 718 code was assigned to the city years ago by the North American Dialing Plan, a group that administers area codes in the U.S.* Mexico, and Canada. "Of the numbers available at the time, 718 was the best*" he said, "There weren't that many available ” The P,S.C. rejected recommendations by a consultant {Economics and Technology* Inc.) hired by the City Board of Estimates. Those recommendations called for the implementation of the 718 area code, however, instead of using it for people* the consultant suggested using it exclusively for computers, paging systems, and other devices, since they were the main reason for the new area code in the first place. [2600 would like to go on record as enthusiastically supporting the idea of an entire area code of machine;.] Supercomputer dialups l |, Ji)sin TwJay Astronomy and astrophysics are gathering so much data by telescope these days* that it cannot be handled by conventional computers* according to Dr Vincent Icke of the University of Minnesota. To remedy the problem, Dr. take called for the creation of a central supercomputer facility that would be at the disposal of all astronomers and astrophysicists nationwide via telephone lines. Wiretap City I he p r >v Vflrt. furo After an investigation, the New Haven (Connecticut) Board of Police Commissioners* a civilian body that oversees the Police Department, revealed in 1978 that the department had routinely tapped the phones of residents from 1964 to 1971, apparently to monitor radical political activity. This* the board said* was illegal. In December 1982, after it had been disclosed that the phones of some JOOO residents had been tapped, the Federal District Court in Bridgeport made the case a class action* inviting anyone who felt wronged to become a plaintiff. So Far, 1230 people have become plaintiffs, They include several judges, lawyers, and other prominent political figures and* of course, a great many members of the Yale faculty. Students Cause Havoc in Computer < firsts Shuikui A group of students at Gompers Secondary School in San Diego tapped into the school's computer system last month, causing uJ| kinds of problems. "It was funny at first when t he kids changed the passwords so the teachers couldn't g ct ' nt0 their programs in the system," said Alex Rascon, a school official, "But then they started deleting grades, altering ihe other kids" homework, and tampering with the teachers' Hies. "These kids art whizzes— ihey're very bright," he went on, "Fortunately we caught it before too much damage was done. At this point it can be easily corrected " Albert Cook, the assistant San Diego superintendent, took the sorehead approach. “We still haven't decided whether charges will be filed with the San Diego Police Department," he said. The Person Numbers Tk AmtcLiKd I'm* Sweden's Person Number is a 10-digit figure that tells who you arc, where and when you were born, and your sex. Every computer file in the country is based on the Person Number, whether it's at a bank, a hospital, an employer, the social welfare office, or the tax authorities. Person Numbers went into effect on January 1 , 1947 and were computerized 20 years later. Recently, a government study suggested the creation of a super-databank (based on the Person Number) that the Central Bureau of Statistics could use freely. By calling up a Person Number on a terminal, the bureau would be able to find out details on everything from a person's illnesses and criminal record to his income and debts. Critics of the plan see this as an erosion of civil liberties. One said, "The files will collect more information on a person than he can remember himself." Furthermore... iMhf Newt * All computers seized by the FBI last October during the Telemail raids haveeilher been returned already orare in the process of bemgsent back. New developments in Lhecasc are expected shortly, * Telenet now hangs up after 3 connection attempts, whether they're successful or not. This means that last month's article {Hacking on Telenet) is already slightly outdated* but only until somebody figures out a way around this latest hurdle. ■ Some more signs of the divestiture— this time it's the : 956 exchange. This is a universal exchange that is {or will soon be) working everywhere. 950-1022 and 950-1088 give alternate long distance dia llones. (The latter belongs to Skyline.) The connection is crystal clear and toll-free, Eventually* the 950 will be dropped and you will dial 1 OX X to make long distance calls* where XX is the carrier of your choice. You can't access 95G's in other area codes, * Eastern Airlines has changed its mind about allowing , portable computers on Bights, leaving only American Airlines maintaining the ban. * 202 and 214 now have automated directory assistance too. Have you cheeked your area code today/ THE FIRST A TOMIC BOMB A TRUE TALC This story was originally related by Laura Fermi, widow of the nuclear physicist Enrico Fermi, who, along with assorted co i leagues, participated in the first test bomb in the desert outside Alamogordo, New Mexico in the early morning hours of a summer day in July. 1945 When the dale had been established for the secret lest, staff members from the Manhattan Project (as the secret test was known } were invited to bring their spouses to New Mexico to watch the results of the several years of research. Each staff member had been assigned specific tasks to handle while there. Generally, they acted as observers and were stationed in a circle around the perimeter of the bomb site. Enrico and Laura were stationed in an area about twenty miles to the southwest of the bomb site. the morning came when the bomb was scheduled to be detonated in the test. Laura told if like this... Enrico and I woke up at 3:00am, to go to the site. The test was scheduled for 4:30am that day, which was July 19, 1945, We drove to our post, about twenty miles from the site. It had been arranged that the nearly one hundred of us present would be Located in a circle a bout 100 milts in circumference surrounding the bomb site. We were all to be tn communication with each other over, telephones, all of which were connected through the exchange in Alamogordo. We arrived at the site at 4: 15 am and almost immediately it began to rain, quite a heavy, very typical torrential downpour during the summer. We waited in our car, and at 4:30 am the time came and went, but the bomb did not go off. Enrico and 1 assumed it might have been postponed due to the rainstorm, but decided to check with the other staff members to see for sure. For some reason, the telephone there at the site did not seem to work; the operator would not respond, (Note: At that time, nearly all phones in the United Slates, and certainly in New Mexico, were manual. No dialing of any sort war possible — you had to use the operator for everything .) Finally Enrico decided that we would drive into town and try to contact the others and see what went wrong. So we drove back to town, and got there about 5:15 am. The only place open at that time of night was a hotel, and we stopped in thereto use a pay phone. Strangely enough, the pay phone was not working either, or at least the operator never came on the line to ask what we wanted. Enrico was quite curious about all this and decided to investigate. We went outside the hotel, and Enrico found where the telephone wires came off the pole and down into the building. He decided that we would follow the wires, so we walked down the street looking overhead at the wires on the pole as we went along. Finally, we turned down one street and saw a house. The telephone poles and wires from all directions seemed to come down to this house. There must have been hundreds of wires from telephone poles all coming down onto the side of this house and going in through an opening Wc noticed that there was a front porch light which was on. The front door was open, but there was a screen door which was closed. We went up on the front porch and looked into the house, A switchboard was there, and there were a dozen or more lights on the switchboard Ik, blinking off and on as pcdple were flashing the switch hooks on their phones trying to raise the operator. The room was just dimly lit, and near the switchboard was a sofa, and a woman was laying on the sofa sound asleep] Enrico pounded very loudly on the screen door, and shouted at the woman. Suddenly she opened her eyes and looked at him, very startled. Then she looked at the switchboard. Immediately she sprang up, dashed over to the board, sat down and began frantically answering the calls.,; Without saying any more, Enrico and 1 left, went back to the hotel where our car was parked, and drove back to our monitoring post twenty miles out into the desert. We had been at our post only about five minutes when the explosion went off, at about 6:50 am, which was two hours behind schedule. Later, we talked to the other staff members and found that there had been some confusion because of the raim None of them had been able to reach the others because the telephone operator had fallen asleep, and the phones were not getting answered /connected... We on the staff all had a big Laugh out of it, but nothing more was ever said or done, and [ doubt to this day that that woman is even aware that the first atomic explosion in the world was delayed two hours because of her. Amazing, but true. Alamogordo was a tiny town back in the 4Q r s, and it's very doubtful that the night operator had ever seen so much traffic in her life as the hundred or so people all on the line at once that early morning. More than likely, the poor dear had had a very rough day the day before, in the miserable summer heat, had been unable to sleep during the day, and had come to work that night thoroughly exhausted. She probably decided that "it won't hurt just to dose mv eyes for a minute ... " and the rest of the story is already told. After alt, experience had taught her that in fact she would not usually get a dozen calls all night on her shift, and she felt relatively safe in stretching out "just for a minute”. Do you have a story about computers or phones? Send it to us! If we print it, you’ll get a year’s subscription to 2600! The address ; 2600, Box 752, Middle Island, NY 1 1953. (continued from page 2) their offices, which takes away the task of having to dial the MCI access number. In addition, you don't, have to enter an authorization code and you don't even have to have touch- tones 6 . You simply pick up the phoneand there's your MCE dialtone! According to MCE, you have to make at least S75 worth of out-of-state calls per month for this system to pay off. Of course, you cant access operators 1 , directory assistance, 800 numbers, and that sort of thing because I) MCE doesn't support any of those services and 2) they're certainly not going to let you connect to something (hey can't charge you for. OF course, if you know what you're doing, you can route calls in such A way that numbers that aren't supposed to go through for you will work, and Cod knows where it finally shows up! This doesn't involve extra codes, blasting the line with tones, or anything overly suspicious. AIL you need is the right combination of area codes. Now this has been proven to work with MCI dedicated lines; it's rumoured to work on dial-ups as well,., Finally, MCI is starting to offer its own phone booths at airports, which we'll report on as soon as wc find one. And of course, there's MCI Mail, an electronic overnight mail service started up last fall which hackers are currently probing. When we get conclusive results on that, we'll pass them along. MCI can be reached at 8006246240. 2600 page The following is a list of hosts that are accessible throu ARPANet* ARPANet connects many systems together, allowing them to sc electronic mall, transfer files, and be able to work on each other computers. The network is very intricate, containing many subnet including the one below, called "MILNET" #■ short for "Military Network That is, our military. This is a small list, encompassing approximate one twentieth the entire number of systems accessible through ARPANe Notice the PENTAGON-TAC below. This Is an access point for people in t government. address: Host name : Host type: Operating H H H H H _ a | i± *■-" * s s s e ^ t; z z ~ ~ ~ ~ ~ 26.0.0.3 NOSC-CC VAX-11/750 □NIX 26 . 2 * 0 * 3 L0GIC0N PDP-11/70 UNIX 26-3,0.3 NPRDC VAX-11 / 780 UNIX 26.0.0.8 NRL VAX-11/750 □NIX 26.1.0.8 NRL-AIC VAX- 11/780 UNIX 26.2.0.8 NSWC-W0 VAX- 11/ 750 UNIX 26.3.0.8 NRL-T0PS10 DEC-10 TOPS 10 26.6.0,8 NRL-ARCTAN PDP-11/40 RSX11 26.7.0.8 NRL-CSS VAX-11/780 UNIX 26.1.0.13 GUNTER-ADAM DEC- 2 060 TOPS 20 26.3.0.13 J ATC-KEES1 BURROUGHS- B/ 29 BT0X/UNIX 26, 0.0+14 CMU-CS-B DEC T 1050 T0PS10 26.6.0.16 RIACS- ICARUS VAX-11/730 UNIX 26.0.0.17 MITRE C/70 UNIX 26.0.0.18 RADC-MULTICS H0NEYWELL-DPS-B/70M MULTICS 26.3.0.18 RADC-TOPS20 DEC- 204 0T TOPS 20 26.5.0.18 RADC-UNIX PDP-11/45 UNIX 26.G.0.1B GE-CRD VAX-11 /780 VMS 26.0.0+19 NBS-VMS VAX- 11/ 780 VMS 26.1.0.19 NBS-SDC VAX-11/7B0 VMS 26.2.0+19 - NBS-UNIX VAX- 11/ 750 UNIX 26.3.0.19 NBS-PL PDP-11/70 UNIX 26+6.0.19 NBS-AMRF VAX-ll/780 VMS 26.7.0.19 NBS-SSI VAX-11/750 UNIX 26.4.0.20 DCA-EMS C/70 UNIX 26.0.0.23 USC-ECLB DEC-1090B T0PS20 26.3+0.2 3 USC-ECL DEC- 109 0B TOPS20 26.0.0.24 NADC VAX-ll/780 UNIX 26.1.0.25 DDN1 C/70 UNIX 26 .0.0. 26 PENTAGON-TAC C/30 TAG 26.3.0.26 TCACCIS-CSC VAX-ll/750 VMS 26.0,0.29 BRL PDP-11/70 UNIX 26.1.0.29 APG-l C/70 UNIX 26.3.0.30 ATC -HANOI BURROUGHS -8/ 29 btos/unix 26+0.0+33 NPS PLURIBUS PLI 26+3.0,33 FNOC-SECURE PLURIBUS PLI 26.0.0.35 N0SC-SECURE2 PLURIBUS PLI 26.1.0.35 NOSC-TECR VAX-ll/780 VMS / EUNICE 26.3.0.35 N0SC-SECURE3 PLURIBUS PLI 26.4.0.35 N0SC-F4 F00NLY-F4 FO0NEX 26+0+0+36 COINS-TAS PLURIBUS PLI 26+1.0.36 HAWAII-EMH C/ 70 UNIX 26+0.0.39 EDWARDS-VAX VAX-11/7B2 VMS 26.1+0+39 EDWARDS-2060 DEC-2060T TQPS20 26. 1.0.45 ARDC VAX-ll/780 UNIX 26.3+0.46 0KC-UNIX PDP-11/70 UNIX 26.1+0+48 AFWL PDP-11/50 RSXllM 26.0.0+49 BBNB DEC- 10 TENEX 26.0,0.50 , DARCQM-TEST VAX- 11/750 UNIX 26.3.0*50 LS5A-DB1 NAS3-5 MVS 26.7*0.50 ctl-ai VAX-11/780 VMS 26.0,0.53 AFSOAD PDP- 11/45 RSX11M 26,2.0.53 AFSODEV PDP-11 /44 RSX11M 26,4.0*53 NCSC VAX-11/750 UNIX 26.5.0.53 martin PDP-11/45 RSX 26.6.0.53 EGLIN-VAX VAX-11/ 780 VMS 26.2.0.54 ACC PDP-11/ 70 UNIX 26*1.0.55 ANL-MCS VAX-11/ 780 UNIX 26.2.0.55 COMP ION -VMS VAX-11/750 VMS 26.0.0.57 TYCHO PDP-11/ 70 UNIX 26 . 2 . 0 * S7 MARYLAND VAX-11 / 780 UNIX 26. 0.0. SS NYU VAX- 11 / 700 UNIX 26.1.0.58 BNL PDP-11/44 UNIX 26.3.0*60 CEC0M-1 F0ONLY-F4 TENEX 26.0.0.61 STL-H05T1 DEC-2040 TOF520 26.1.0.61 ALMS A- 1 VAX-11/ 750 UNIX 26.1.0.64 MARTIN -B VAX-11/750 VMS 26,3.0.64 ROBINS-UNIX PDP-11/45 UNIX 26.0.0.65 AF5C-5D DEC-2020T TOPS20 26.2.0.65 AEROSPACE VAX-11/780 UNIX 26* 3.0*65 ' MARTIN -ED PDP-11/45 RSXUM 26.1*0*66 AFGL PDP-11/50 RSX11M 26*3*0*66 MITRE- BEDFORD VAX-11/ 780 UNIX 26.0,0*67 AFSC-HQ DEC-2040T TOPS20 26.1-0.73 SRI-HARF PLURIBUS PLI 26.4.0.73 SRI-F4 F00NLY-F4 TENEX 26.0.0.74 SIMTEL20 DEC-20 4 0T TOPS 20 26.1.0.74 HSMR70A C/70 UNIX 26.3.0.74 WSMR70B C/70 UNIX 26.3.0.78 MCCLELLAN PDP-11/ 70 UNIX 26.0*0.81 NEMS VAX-11/750 UNIX 26.1.0.81 NALCON VAX-11/750 UNIX 26*3.0*81 DTRC VAX-11/780 UNIX 26. 0. 0.82 BBNCCT C/70 UNIX 26.3.0*82 DDN2 C/70 UNIX 26.4.0. 82 BBN-RSM PLURIBUS PLI 26.9*0*82 TEPI C/30 26.0.0.87 SANDIA DEC-2O60T TOPS 20 26 .0*0* SS NLM-MCS VAX-11/780 UNIX 26.0.0.90 LANL VAX-11/750 UNIX 26.4,0+92 NAVDAF- NEWPORT UNI VAC- 1100 CMS 26.1,0+95 Sl-A FODNLY-F2 WAITS 26*2,0,95 Sl-B VAX-11/750 UNIX 26.3.0.95 Sl-C VAX-11/750 UNIX 26.2.0.97 FAXRV-NES VAX-11/730 VMS 26,1.0.103 USC-ISIE DEC-1090T T0PS20 26.2*0.103 ADA- VAX VAX-1 1/ 780 VMS 26.3.0.103 use- IS I DEC- 1090T TOPS20 26.1.0.104 DC EC-LSUS2 IBM-15& MVS/SP 26,4.0.104 DCEC-LSUS IBM-158 MVS /SF 26.3.0.106 ARPA-PNG11 PDP-11/34 EPOS 26.0.0.112 STL-HOST2 BBN-C/60 UNIX 26.0*0.117 KOREA- EMH C/70 UNIX 6