perm filename HOTER.DOC[ESS,JMC] blob
sn#166622 filedate 1973-03-09 generic text, type T, neo UTF8
THE HOME INFORMATION TERMINAL
by John McCarthy
Visionaries have often proposed that homes 1. The average citizen is a TV fan and
be equipped with information terminals each doesn't read anyway. In the first place, our
consisting of a typewriter keyboard and a screen system doesn't need so many subscribers to be
capable of displaying one or more pages of print economical. Secondly, after I have described
and pictures. The terminal is to be all the bells and whistles, you will see that
connected by the telephone system to a time- even the TV fan will be tempted, and you - oh
shared computer which in turn has access to files socially conscious reader - may even want to
containing all books, magazines, newspapers, coerce him into buying one or coerce the
catalogs, airline schedules, much additional government into giving him one for free.
public information not now kept, and various
files personal to the user. 2. How can you think of one more convenience
and comfort when the world will come to an end in
Through the terminal the user can get ten years unless menaces A, B, and C are dealt
any information he wants, can buy and sell, with immediately. In the first place, I don't
could communicate with persons and think the world is about to come to an end or even
institutions, and process information in other that it is getting worse, and we Americans like
useful ways. Such a system has never come about new gadgets. In the second place, you will see
because it costs too much, but with each advance that the new information system will make the
in technology, it becomes more feasible. I public more responsive to the careful
think that the technology of computers, time- reasoning of you good guys and more immune to
sharing, terminals, and application programming the crude propaganda of those bad guys.
has advanced to the point where realistic
estimates are possible of the remaining advances In order to see the effects of the new
necessary to make home consoles feasible and information system, suppose that all book and
useful. In this paper, I shall discuss the uses newspaper information were so distributed. What
of the home terminal, some potential beneficial changes would occur?
effects on society, estimate how far we are from
a system people will pay for, and advocate some At present, a newspaper or a book is a
pilot projects, some standardization efforts, package produced by a large organization.
and some laws and regulations to prevent In our new system, the physical production
monopoly and secure adequate competition. disappears, allowing a much smaller organization
to put out the same packages of text and
We can start with ordinary reading. To pictures. Moreover, the user does not face a one
get a newspaper or book, I type its name or number shot decision to buy Life or Look. He will be
and the first page appears. The most obvious able to read the "cover" or table of contents
benefits are: of each, read such items as strike his fancy, and
the system will bill him for what he reads
1. I can get any document instantly. from each source. In fact, since the cost of
keeping a file of information in the computer and
2. My house isn't full of paper to be making it publicly available will be small, even
sorted and put on shelves and dusted or put in the a high school student could compete with the
trash. Trees aren't cut down, and air pollution New Yorker if he could write well enough and if
doesn't result from burning the stuff. word of mouth and mention by reviewers
brought him to public attention. What, then,
Some immediately apparent disadvantages are: is a publication in the new information system?
1. The expense. I'll deal with this later. A publication is an organization that puts
out a list of material it has edited and
2. I can't read in bed. The book size recommends to its readers. It helps its authors
portable terminal will come later. A household produce material that it thinks will suit the
may require several terminals or perhaps we may readers, and it has a financial arrangement with
have to compromise with sin and provide a hard them about splitting the proceeds.
copy terminal after all.
There can be a wide variety of
There are two other immediate negative publications of different standards of writing and
reactions:
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editing and different budgets for carrying out Famous authors will not need publishers
these activities. However, they will all be because their loyal readers will have the system
equally accessible to all readers, and the only find their stuff automatically.
justification for an expensive editorial
organization will be that it can produce a more To summarize: the new information
popular package. The price of reading a package system will promote intellectual competition by
can be set by the publishers. reducing the price of entry, will permit readers
to be selective, and will allow authors to
A reader may feel that he needs help in revise material until they are satisfied that
finding his way through the totality of it withstands criticism as well as it ever will.
literature available to him. Various people will This should make intellectual life more
be eager to make a living by providing it. ⊂ A interesting.
bookstore or library is a program that when
called shows the "covers" of publications. The financial aspect of writing would
Reviewers will produce lists for him and make presumably be as follows: a piece of
money when he reads their lists or by written material has a price for reading it.
kickbacks from the publishers. "Reading advisers" (This price may be zero for amateur writing,
under some catchier name will offer to generate political propaganda, advertising, and for
lists just for him according to a profile of his scientific journals). The reader's account is
interests. debited and the account to which the
material belongs is automatically credited.
Advertising in the sense of something that The reader will have the system balk at what he
can force itself on the attention of a reader will considers overpriced material.
disappear because it will be too easy to read
via a program that screens out undesirable The new information system will have a
material. However, people will still want to know profound effect on buying and selling.
what is for sale and will still want to see Sellers of movies, groceries, automobiles,
the seller's story about why they should buy it. plumbing services and cures for baldness will find
Probably, Life will still be able to get money it advantageous to list their wares in the
from advertisers; many people will still want to information system together with current prices
know what is advertised in Life, but those who and availability. The user can place an order
don't want to know will be able to avoid it through the system as he can by telephone, but he
automatically. can do much more:
Another effect is the possibility of 1. He can call on someone's program to
frequent revisions of articles and books. scan the sellers of sports cars and propose what
An author can take into account new facts or other it considers the best deal. This program might
people's criticisms, and the revision will even negotiate with programs representing the
take effect immediately. This raises sellers.
1984ish possibilities, so it must be provided
that old versions remain available. Those who 2. He can tell the system whether
suspect the whole system will keep their own last year's cure for baldness worked and a get a
copies of favorite material in their private summary of the opinions of those who bothered
files, on microfilm, or even on paper. to record their opinions of the cure he
contemplates trying now.
Public controversy can be carried out more
expeditiously than at present. If I read 3. He can make an airplane or hotel
something that seems controversial, I can ask the reservation by interacting with a program the
system if anyone has filed a reply. This, airline or hotel reservation company has written
together with an author's ability to revise to tell him what is available. He need not
his original statement, will lead people to suffer the delays you now get when you call an
converge on considered positions more quickly than airline or travel agent at peak hours.
at present even if they do not come to actual
agreement. 4. Individual design and construction
services can be offered through the system
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although this requires the development of computer using an editor program. It allows easy
controlled manufacturing techniques for various revision, can be made to check spelling,
types of article. The idea is that automated grammar, and punctuation, and will produce
design programs can produce designs for justified or other forms of elegant output and
articles meeting individual specifications. also indexes.
Either by himself or in consultation with an
expert, an individual would use the system to 3. Filing. Keeping personal files in the
proa design and display how it would look and computer has great advantages once documents can
possibly how it would perform. Candidates be entered without retyping them, either
for individual design include clothing, furniture, because they have been prepared in a computer
boats, electronic equipment, houses, and even readable form or because a suitable page reader is
cars. The system would then produce the available. Namely, one can retrieve any
instructions for controlling machine tools, fabric document on the basis of its characteristics
cutters, and also printed instructions for the without having taken the trouble to file it
hand parts of the operation. In general, it properly in the first place.
should be possible to make single objects at
little more cost than present mass produced 4. Education. Computer aided instruction
objects. In some cases, there would even be (CAI) has advanced to the point that a number of
savings, because mass production requires courses or aids to traditional courses have been
estimates of demand that are often wrong developed and have been shown to be useful.
resulting in inventories that are expensive to The main obstacle to the widespread use of
sell or even have to be sold at a loss; the cost CAI is economic, but new developments in
of this is made up by a general increase in display technology and communications give
prices. a reasonable probability of cost-effective
systems within this decade. There is no special
There are many more useful services problem in having these systems available in the
that can be offered through the new information home as well as at school. This would be
system and again the system is conducive to aided by standardizing course writing languages.
competition. Writing and storing a program and Again, we should try to stimulate competition
announcing its availability can be a very low by encouraging the offering of courses in
capital operation, and the system can collect particular subjects independent of the schools.
whatever price has been set for its use.
The development of such a system is
We could go on listing services that would probably inevitable (unless it is forbidden
come to be offered in a fully developed system, by law) as soon as costs come down to the point
but now we shall list some services to smaller where it is profitable for time-sharing service
groups of users that are cheaper to provide and bureaus to offer services to individuals.
which will help get the system started. However, favorable policies will bring this about
sooner and will make the effects better.
1. Calculation and facilities for
writing, running, and debugging computer The main danger to be avoided is the
programs. This doesn't interest the general creation of services of limited scope that
public much, but it is the present bread and through some avoidable feature cannot be expanded
butter of the time-sharing service bureaus to provide the services mentioned here and many
that will grow into the new information system. more. Another problem is to avoid
At present, these service bureaus offer very monopolies; the intrinsic nature of the system
convenient way of doing small scientific and permits any person who can write computer programs
engineering calculations, but do not offer to compete with large organizations in
reasonable prices for big computations, and are inventing and offering imaginative services, but
only beginning to offer useful services to one can worry that the system might develop
business firms. commercially in some way that would prevent
that. In general, we should try to develop
2. Editing. Anyone who writes information services in such a way as will enhance
(writers, journalists, scientists, advertising the individuality of its users.
men, engineers and students) will benefit from
3
Between us and the home information require long holding times, short response
system lie a number of problems, some in times, and much higher transmission rates from the
developing suitable low cost terminals, some computer to the user than in the other direction.
in programming technology of time-sharing,
some in the economics and politics of For the purposes of the home terminal,
communication systems, and some in the attitude the speeds of transmission over present
of the public and government towards innovation. unconditioned voice grade circuits are a bit too
In the following sections we shall discuss these low for such applications as reading. 1200 bits
problems. per second would take 20 seconds to transmit a
typed page and about four times that for a page of
How we get there from here. a dictionary. Eight times this rate is obtained
over conditioned voice grade lines, and this
1. Consoles. might be barely adequate. Perhaps a better bet
is the transmission facility planned for the
The quality and price of display Picturephone service now being introduced
consoles is rapidly improving. At present, one experimentally, but the cost of this service
can add a display console with keyboard to our for long holding times is not yet
laboratory system for about $700, but to add determined. The most economical system might be a
another port on the system so that the number of specially designed store and forward system
consoles active at one time is increased by one configured to give fast turn around for short
costs about $2500. A reasonable display console messages.
that can be located at the end of a telephone line
now costs about $10,000. These consoles are Whether such a service will be made
adequate for any of the services mentioned in available depends on political as well as
the previous section, although for reading technical factors. For example, if on the basis
purposes, it would be desirable to be able to of present plans, the digital communication
display more than 35 typed lines at a time. market is divided by regulatory action among AT&T
and its potential competitors, it might turn out
In my opinion, the cost of an adequate that no-one is obliged or even allowed to offer
display terminal that can be located at the end of the service required for home terminals at a
a telephone line will be in the $500 to $1000 reasonable cost.
range by 1975 even without a market of the
size of the potential home terminal market. 3. Computer technology.
The business, engineering and science, and
government markets will be large enough and At present, computer technology can
price sensitive enough to bring this about. offer the services required for the home
terminal at a reasonable cost, provided
Another contender as a terminal is the computer configurations are optimized for the
plasma panel, but the above estimates are based purpose, provided reasonable load factors can be
on CRT terminals with a mini-computer and an obtained, and provided there are reasonable
integrated circuit memory. economies of scale. Unfortunately, IBM
computers are organized in such a way that time
2. Communications. sharing is very expensive because of their
interrupt structure, their expensive terminal
In the United States, the multiplexors, and their dedication to the
facilities for digital communications are archaic half duplex method of
growing rapidly but in a rather disorderly way communication. The other major computer
because of the multiplicity of requirements manufacturers such as CDC, General Electric, and
of the different applications. Some Univac are not in much better shape since they
applications such as credit verification require offer for time sharing, machines that were
very low cost short communications with turn optimized for other purposes. Smaller companies
around times of seconds. Others require very low like DEC are in a somewhat better position.
cost per bit but can stand delays of minutes and However, none of these difficulties are
hence are candidates for low performance permanent, and better organized computers may be
store and forward systems. The terminal systems expected once the factors in computer design
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that make for good cost-performance in time with texts that are just regarded as sequences of
sharing become clearer to the manufacturers. latin letters.
The present magnetic disk storage units are 3. The biggest task, however, is the
a bit marginal in cost effectiveness for use with application programming itself.
home terminals. Thus storage on the new IBM 3330
disk would cost a user about $.03 per month to 5. Commercial organization.
store a typewritten page making storage of
extensive personal files expensive and private From a social point of view, one of the
copies of books at $5 to$10 per month attractive features of the provision of time-
prohibitively expensive. This would not be too sharing services is that it is not a natural
expensive for national libraries, but it would be monopoly. Communication is cheap enough
economically very difficult to get enough readers for teletype based time-sharing so that with
to support the storage of books on magnetic local multiplexors, time-sharing bureaus can
disk files in the near future. compete all over the United States. In principal,
it should be possible to have world wide
Fortunately, much larger files are becoming competition. The major force that might tend to
available. The laser file made by Precision reduce competition is the exclusive possession of
Instruments Inc. is claimed to store a trillion proprietary programs or files. Therefore, it
bits and costs $1,000,000. This comes to about $4 is desirable to separate the ownership of
per book which is reasonable even for single programs performing services from the ownership
copies. Mass production of such files will reduce of the service bureaus themselves and to
the cost even further. encourage enough compatibility between different
time-sharing systems so that the owner of a
4. Computer programming. service program could provide it on a number
of machines. It is also important that important
The basic technology of writing time files be accessible and modifiable with
sharing technology is reasonably well developed in suitable protections by actions initiated on
that cost effective systems have been written, other machines than the one that maintains the
but there is still a lot of chasing of willow-the- file.
wisps and quite bad time-sharing systems are
often produced by otherwise competent firms. 6. Needs for research and development.
Before the programming required to offer the
services mentioned in the first part of The hardware required for home consoles will
this paper can be accomplished some further be too expensive for extensive systems for
advances need to be made including at least the probably another five years. In the
following: meantime, research and development should be
undertaken in the following areas:
1. The interactive and file reference
aspects of programming languages and time sharing 1. Standardization of the interfaces of
systems need to be standardized so that an time-sharing systems and their languages.
interactive system written in one system can be
used in another that uses different hardware and 2. Experimentation with services. At
a different time sharing system. Without this it present, it is very difficult to get support for
will be very expensive for new user services to development of generally useful services unless
get large markets unless some particular time either it can be claimed that disaster will
sharing system gets a monopoly. result from failure to support the activity or
that the supporting organization will itself
2. A system needs to be developed for make a profit. This political fact is one of the
representing text in a computer that will include reasons for the concentration on military
the full variety of alphabets, type fonts and technology in the recent past.
character sizes and also be adaptable to
diagrams, drawings and photographs. The consoles 3. Research aimed at devising ways of co-
also have to be adapted to this variety of styles. ordinating the great variety of time-sharing
This is an ultimate requirement; much can be done services into a mutually communicating
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network. Neither sufficient understanding nor
sufficient political or commercial force is
available to cause the development of time-
sharing services to proceed according to a
unified plan. Nevertheless, computers are
flexible enough so that originally
incompatible systems can be made to communicate
and use each other's services. Experiments
with the ARPA network that provides
communication between U.S. Government sponsored
research computers will provide useful
information.
7. Comments on the conference.
In general, the conference showed a poor
situation in the scientific and technological
community and also the public affairs community
regarding technology and the human future. There
were a few technically competent but rather
narrow surveys of the state and prospects of
particular tool areas of technology. There was
much random doom-saying and denunciation of
currently fashionable whipping boys. There was a
fair amount of opinion that certain things should
not be done. There was an almost total
lack of imaginative discussion of the
opportunities technology offers us to improve
human life. This lack was especially notable
in those individuals and organizations that are
supposed to be professionally concerned with the
matter.
This essay is part of an effort to correct
the imbalance.
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