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 <AWALKER AT RUTGERS>
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 <FAILURE>
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
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