perm filename CSDDIS.DOC[ESS,JMC]1 blob sn#026620 filedate 1973-02-28 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:

      1. Integrated circuit raster memory     $73K
      complete with buffer registers
      and power supplies,based on
      prices paid by Yale and quotes
      to M.I.T.

      2. Keyboards                            $14K
      (70 keyboards at $200,
      based on quote by Microswitch)

      3. Monitors                             $14K
      (70 monitors at $200,
      based on quote by Ball Bros.)

      4. PDP-11/40 with 16K words             $20K
      (D.E.C. published prices)

      5. Shift registers and
      control electronics                      $5K

      6. Video switch                          $9K
      (cost of video switch built by AI Lab)

      7. Keyboard multiplexer                  $8K

      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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