perm filename CSDDIS.DOC[ESS,JMC]2 blob
sn#028901 filedate 1973-03-14 generic text, type T, neo UTF8
A DISPLAY TERMINAL SYSTEM FOR THE COMPUTER SCIENCE DEPARTMENT
This is a plan to equip the Computer character sets used in programming and in
Science Department with a system of keyboard and mathematics have proliferated to the point where
display terminals for use in teaching and allowing each user to have whatever characters
research. The terminal system will make he wants is the only solution compatible with the
accessible to department faculty and graduate goal of using any computers that are available to
students from their offices the IBM 360/67 in our faculty and students.
the Computation Center, the PDP-10 in the
Artificial Intelligence Laboratory, and through 4. Printing facilities compatible with the
the PDP-10 any computers on the ARPA network that above should also be available but not
they may have made arrangements to use. This necessarily with each terminal. In fact, there is
includes, for example, the ILLIAC 4 at Ames no present way of making such facilities
Research Center. Connections to other campus available to each terminal but suitable
computers can also be arranged. public printers can be had, for example the Xerox
XGP. The cost of adding such a printer has
In our opinion, such a terminal system not yet been determined, but there is a strong
together with suitable hard copy output in the demand for it, and its cost will be included in a
most important laboratory and teaching future version of the plan.
facility that a computer science department can
have. The interests of the faculty and students The scheme proposed has the following
are too varied to be satisfied by any one computer characteristics:
since no one computer will have all the
hardware and software facilities that are of 1. The display image for each active user
research or teaching interest. is stored as a 512x512 raster in an integrated
circuit read-write memory.
The plan we are now proposing is based in
part on a study made by John McCarthy at 2. There are 64 terminals, but only 32
M.I.T. in fall 1972 in support of a plan to get a memories so that only half of the terminals can be
terminal system for Project MAC and the Artificial active simultaneously. However, a low duty
Intelligence Laboratory. In this study, cycle is to be expected if the terminals are in
requests for proposals were sent to leading offices so this is ok.
firms in the display field and the replies were
evaluated. The best plan, however, was found 3. The cost to add a terminal to the system
to be scheme being developed by Peter Wiener of is about $500, and the cost to add a
Yale University, and our plan is based on the memory is about $2200 now, but a large
Yale scheme which is also being followed by reduction is expected in less than two years as
the M.I.T. Artificial Intelligence Laboratory. 4096 bit memory chips come into production
The Stanford Artificial Intelligence replacing the 1024 bit chips on which the
Laboratory also hopes to upgrade its Data Disk present prices are based.
display system to the new standard.
4. The system is controlled by a mini-
The goals that we want to achieve are the computer, say a PDP-11, which communicates with
following: the host computers (initially the IBM 360/67 and
the PDP-10), and writes characters and
1. A terminal in each office used by pictures by directly addressing the display
faculty and graduate students. This requires memories. The displays are maintained by a memory
very low cost terminals. port that reads bits from the memories into
shift registers and transmits them together
2. A large terminal facility for the with synchronization signals through a video
use of students in courses. About half the switch to the displays over coaxial cable.
terminals would be available for this
purpose. 5. Each display is connected to the central
unit containing the memories by an individual
3. Each terminal should be capable of cable, and the keyboards are connected to the
displaying at least half a page of arbitrary keyboard multiplexer by twisted pair unless it
character sets and also graphics. The turns out to be feasible to transmit the
keyboard signal back on the same coaxial cable as Not included in these costs are engineering
is used for the video. which we hope to do with volunteer labor and
wiring costs. The necessary programming will
6. The video switch is a 32x64 electronic also be done within the Computer Science
crossbar. It will be a copy of a unit now Department. Maintenance of the system should
in use in the Artificial Intelligence cost about $5000 per year counting student labor
Laboratory's display system. and parts costs.
7. In the initial version of the system all Perhaps $50K of the costs can be obtained
characters and vectors are produced by software from projects. The AI Laboratory should pay
in the mini-computer. A PDP-11/45 will take 150 for its connection and the cost of the terminals
microseconds in the worst case to write a used by project members on campus. With NSF
character. If the host computers can support a not giving facilities grants any more, the
higher rate of character writing then a special outlook from that source is not bright. We
character writer can be added. believe that the University should pay the main
cost as the major laboratory instructional
Here are the components of the proposed and research facility of the Department.
system and their estimated costs:
Regrettably, there are a few costs not yet
1. Integrated circuit raster memory $73K listed above. The major one is stringing the
complete with buffer registers cables, and this has not yet been explored. The
and power supplies,based on cost of the cable itself is not large - 4 cents
prices paid by Yale and quotes per foot, but the cost of stringing it may be
to M.I.T. significant. If we figure 500 foot average cable
length, we get $20 per terminal for the cable or
2. Keyboards $14K $1280 altogether for the bare cost of the coax.
(70 keyboards at $200, The cost of the keyboard cable will be less.
based on quote by Microswitch)
The AI Lab is hiring an expert programmer
3. Monitors $14K and digital engineer who is presently building a
(70 monitors at $200, Yale type system at M.I.T. He can help with this
based on quote by Ball Bros.) work, but he is not free.
4. PDP-11/40 with 16K words $20K A recent survey of offices in the Computer
(D.E.C. published prices) Science Department turned up 57 locations where
terminals would be wanted. I am not sure whether
5. Shift registers and secretaries were included as they should be
control electronics $5K according to AI Lab experience. This suggests
that a somewhat larger system would be wanted if
6. Video switch $9K we are to meet all CSD demand and provide a
(cost of video switch built by AI Lab) substantial terminal room (at least 16 terminals)
for students. Therefore, we recommend $200K as
7. Keyboard multiplexer $8K the total cost of the project not counting any
overheads.
8. Connection to PDP-10 $15K
9. Connection to the IBM 360/67 $10K
(in addition $300 per month rental
for IBM hardware is required)
10. Contingencies $10K
TOTAL $178K
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