Aucbvax.1342 fa.human-nets utzoo!duke!mhtsa!eagle!ucbvax!DERWAY@MIT-ML Tue May 12 21:06:01 1981 HUMAN-NETS Digest V3 #98 HUMAN-NETS AM Digest Wednesday, 13 May 1981 Volume 3 : Issue 98 Today's Topics: Query Replies - WHT and Cable & Voice Grade Line Bandwidth & speed dialing, Communicating via Network - Human Communication, Computers and the Handicapped - Color Blindness, FYI - Xerox STAR, Humor - Reliable Computing ---------------------------------------------------------------------- Date: 12 May 1981 0345-PDT (Tuesday) From: Lauren at UCLA-SECURITY (Lauren Weinstein) Subject: replies to technical queries Let's see if we can answer a couple of technical questions brought out in a recent digest... RE: Channel 68. I am assuming that Channel 68 is a standard UHF STV broadcaster, using one of the several common scrambling systems. There are two problems with attempting to receive the scrambled programming via the cable: 1) STV and Cable companies often have contractual agreements NOT to mix premium programming. In other words, cable companies often resist allowing the STV companies to attach descrambling boxes to their cable (they have the right to legally prevent such attachments). The motive is clear -- most cable companies these days either provide their own premium programming (such as HBO, Movie Channel, Cinemax, Rainbow, etc.), or soon plan to. I might add that in most cases, the cable-based programming is superior. Several of the satellite-based services run 24 hours a day -- much more convenient for persons who live during "strange" hours than 2 or 3 movies run in the evening by the STV outlets. 2) Generally, the STV outlets only build one basic descrambler box for each market. These almost always have a simple crystal-controlled UHF tuner permanently tuned to the appropriate UHF channel. The cable companies almost universally move all "local" UHF channels down to VHF (2-13) or MIDBAND/ SUPERBAND (channels 14-37 on cable converter boxes, often designated by letters from A-X, etc.) These cables DO NOT pass "real" UHF. Different cable companies might move the same UHF channel down to totally different VHF/MIDBAND/SUPERBAND channels, depending on their channel mix. Providing service under these conditions would require a special box capable of receiving whatever channel the cable company uses instead of the actual UHF channel. While such boxes could be built, and could even be made switchable between channels without much trouble, there is little interest in doing so. I have seen some cases where special boxes were provided for this purpose, but it seems to be pretty rare. I might add that there are situations where cable companies, who perhaps don't have the money for a satellite earth station, contract with a local STV supplier to pump that signal into the cable. In these cases, they usually have an STV descrambler at the cable headend, then RE-SCRAMBLE the signal using a different system for which cable boxes are available. In other cases, the signal might just be "trapped" out at the homes of cable subscribers who are not paying for the premium service. One other issue: some cables are so technically poor that the STV signal could not be decoded in ANY case. Descrambling data that the STV boxes need might be squashed, and even the audio subcarriers on which the "real" audio is hidden can be damaged. ---- One problem with trying to get 9600 baud over a simple leased line (and I have considerable experience in this!) is that telco lines of almost any length are "loaded". That is, they have various coils and other goodies installed to prevent longitudinal imbalances and other horrid things that go bump in the night. This loading means that impedance, resistance, capacitance, bandwidth, etc. go to hell. However, the whole thing is designed to provide "adequate" voice service -- and that it generally does. Feed a nice clean signal into a leased line one day and take a look at the output on the other end on a scope. It's crushed city, man. If you want high speed data, simply pay a fortune (and be willing to wait for months, if you're lucky) for a conditioned line. Good luck. --Lauren-- ------------------------------ Date: 6 May 1981 0136-EDT From: Hobbit Subject: ESS [reply to Ian Merritt] Down here in Jersey, the *n convention doesn't work... It is universally n# or nn#. You must be from old Totalphone territory, when they first came out with the non-programmable speed calling as mixed in with all the other features. Jersey never had Totalphone, but started with individual 'custom calling' features. Since they never had the *n convention here, they didn't have to implement it for compatibility with the people who were already used to *n. I could go on forever about New Jersey Bell... couldn't we all! FERNS, eh? Haw! Haw! Haw! _H* ------------------------------ Date: 6 May 1981 0359-EDT (Wednesday) From: Gary Feldman at CMU-10A Subject: Sociology of Computer Science With respect to the assertion from Human-Nets V3 #92 ... this is because there are a fair number of gays in computer science ... Is there any reason to believe that the percentage of gays in computer science is different from the percentage in the general population (or more properly, in the work force)? I can relate this to two observations: 1. The commentary to the Hacker Papers (Psychology Today, Aug 80), Weizenbaum (1976), and others observe that many people appear to use computer interactions as a substitute for human interactions. 2. Many gays experience a sense of isolation before they manage to meet other gays, thus giving them a need for the sort of interactions mentioned above. In the language of Transactional Analysis, it could be claimed that computers can provide "strokes" which are as useful as those provided by people. One case which comes to mind is the young man from Michigan who committed suicide last year and who made the news with his disappearance the year before. He was a computer whiz, was involved with gay groups, and (as an aside) was a Dungeons and Dragons player. He was also (according to news accounts) a very lonely person. The answer to this question may provide insight into the general question of what sort of people get involved with computers, and why are there so many compulsive computer users. It also relates to the discussion about communication of emotion via computers (which also started as a plea against loneliness). P. S. wrt stereotypes: some of the most macho football players on frat row ARE gay. ------------------------------ Date: 9 May 1981 (Saturday) 1132-EDT From: DREIFU at WHARTON-10 (Henry Dreifus) Subject: Color Jeff, Indeed that is a problem for those who are suffering from Color Blindness. The future of computers / human-factors will indeed use color, perhaps quite extensively. The proposed solution is to change the colors in the Video Lookup Table of that graphics display so the person can percieve 2 different colors. Some thought has been given to this situation. There are 2 major types of color Blindness: Red-Green and Blue-Yellow. There are far more R-G color-blind people than B-Y. Initially, in Europe they made red into Orange and the green more blueish white. Over 'there' people seem to prefere Amber [perhaps a result of Monarchies?]. The color blind people (they usually know they are Color Blind) are permitted to select base colors for their use. By introducing an additional color to one of the 2 they are able to distinguish them. For those who are not that familiar with color-blindness, it is described as a disorder in which a person cannot distinguish between two colors. The colors must be complimentary, since the eye has 'sets' of receptors for color pairs. Thus the R-G and B-Y pairing. One who is color blind can not tell the difference between the two colors because there is some damage or disorder to the receptors (rods?). ------------------------------ Date: 9 May 1981 (Saturday) 2307-EDT From: SHRAGE at WHARTON-10 (Jeffrey Shrager) Subject: Letting the colorblind user at the color tables... Unfortunately this is no solution since it is only good for those persons that happen to be programming the system in question. I don't really care about those persons--they could even do something as simple as change the numbers in their programs. The concern lies in the use of graphics in public (like the color in traffic lights). The guy reading a plane time schedule in the airport that is color coded with read and green is not going to be able to go patching the color tables for himself even if he (a) knew that they were wrong and (b) had access to the computer that ran the display. ------------------------------ Date: 9 May 1981 0957-EDT From: Hank Walker at CMU-10A Subject: color blindness I am partially red-green color blind, and I do a lot of VLSI work, which is usually done in color. I don't seem to have a problem because the colors are sufficiently different, and there are other geometrical cues. As a matter of habit, I do all of my layout work in pencil. I have no trouble understanding it, or black and white xeroxs of color drawings, but most other people seem to have great difficulty. So this seems to be a case where I can get by, plus handle situations that others can't. They could understand B/W pictures too if they took the time. ------------------------------ Date: 9 May 1981 00:31:59-PDT From: CSVAX.halbert at Berkeley Subject: Color blindness I am one of those people with medium-grade red-green colorblindness. I once took a test at Polaroid which said I was actually yellow and purple deficient. Green traffic lights look white to me, which makes them hard to distinguish from streetlights from far away. I have absolutely no trouble distinguishing the green from the red traffic lights, but yellow and red is sometimes a little tricky (the cue is that the yellow is brighter and lighter). I also have a lot of trouble naming, though not necessarily distinguishing, earth-type colors, such as brown and green, tan and green, etc. I have good night vision, but it takes me a long time to see anything in a darkroom lit with a red safelight. Right now there are surprisingly few things in daily life I must deal with that use color cues. Sometimes it's hard to read resistors, but then I just use an ohmmeter (and test 'em at the same time). But I had a lot of trouble when I took a VLSI design course; I had to choose my colored pencils carefully. The thin lines used in stick diagrams were particularly hard to distinguish, which says to me that I may be distinguishing some colors based on intensity rather than color. But I am worried that people will use color more in the future. Red and green LEDs for yes/no indicators are particularly annoying and possibly dangerous for people more color-blind than myself. I have to see them both on, apparently so I can judge intensity differences. Red and blue would be much better (how about blue LEDS, you semiconductor physicists?). Red and orange are also troublesome. What I would say is that nothing vital should be based solely on color cues. Associate shapes, positions, or labels with the use of colors so we poor folks can tell what's going on. --Dan ------------------------------ Date: 3 MAY 1981 2058-PDT From: CBARNEY at USC-ECL Subject: Xerox Star One interesting fact about the Star is that you cannot access HUMAN-NETS over it. The Star will talk only to Ethernet. If you also have a $15,000 Xerox communications box you can emulate a modem; but as is, the Star cannot shine in the outside world. Xerox promises a modem sometime in the indefinite future/. ------------------------------ Date: 6 May 1981 1722-EDT From: GEOF at MIT-XX Subject: WORLD-NET reliable programs I just heard a lecture on I just heard a lecture on tandem computers. It brought tandem computers. It brought to mind an interesting way of to mind an interesting way of achieving reliability using achieving reliability using WORLD-NET. WORLD-NET. The idea is for people on this The idea is for people on this side of the world to cooperate side of the world to cooperate with computer operators on the with other side of the world. With a network connection between ection between the two computers, the primary the two computers, the primary process could be here, and the process could be here, and the backup could be in Africa backup could be in Africa somewhere. The advantage? somewhere. The advantage? Better use of computers, since Better use of computers, since our peak hours are the same as our peak hours are the same as their slack ones. their slack ones. ------------------------------ End of HUMAN-NETS Digest ************************ ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.