PLATO Notes: Original Development
In the summer of 1973, Paul Tenczar asked me to write a program
that would let PLATO users report system bugs on-line. Tenczar
was the head of the system software staff, and I was a 17-year
old university student and junior system programmer. I had been
with CERL for about a year, learning the ropes and doing minor
programming tasks at minimum wage.
We already had a way for users to report bugs, but it was just an
open text file called "notes". Anyone could edit the file and
add a comment to the end. After investigating a problem, a
system programmer would insert a response (typically something
like "+++Fixed - RWB").
This was simple enough, but there were problems. For one thing,
only one person could edit the file at a time. For another,
there was no security at all. It was impossible to know for sure
who had written a note. Most people signed or at least initialed
their comments, but there was nothing to enforce this. And
occasionally some joker would think it was fun to delete the
It was just such an incident that prompted Tenczar to ask me to
develop a replacement. His idea was a simple refinement of the
method we had been using: a user would type a problem report
into a special-purpose program, which would automatically tag it
with the date and the user's ID and store it safely in a tamper-proof
file. The same program would allow convenient viewing of
the stored notes. Each would appear on a split screen, with the
user's note on the top half and the system staff's response
It occurred to me that half a screen might not be enough space
for some notes. And that some problems might require back-and-forth
conversation between a user and the system staff. A limit
of one response per note wouldn't permit much dialog.
I came up with a design that allowed up to 63 responses per note,
and displayed each response by itself on a separate screen.
Responses were chained together in sequence after a note, so that
each note could become the starting point of an ongoing
conversation. This is what John Quarterman calls a star-structured
conferencing system, and PLATO Notes was apparently
the first of its kind.
My first prototype kept all notes in one file. Upon entry you
would see an index of the most recent notes, listing each note's
number, date, title, and number of responses. You could then
select a note to read, or page back through the index to find
As I showed this to other members of the system staff, we began
to talk about other ways that this program might be used beyond
just problem reports. We thought it would be nice to have a
separate area where new users could ask questions and get help
from more experienced users, and another area where the system
staff could announce new PLATO features. So I added a top-level
menu to let people choose among three notesfiles: System
Announcements, Help Notes, and General Notes.
Notes was released on August 7, 1973. It was named after the
text file it replaced, so that people accustomed to typing
"notes" would be taken to the right place.
Every note or response appeared on its own screen. Since PLATO
was designed for education, its architecture was biased toward
carefully crafted full-screen displays. It was easy to place
text or graphics at specific locations on the screen, but nearly
impossible to scroll text. For Notes, this was both an advantage
and a drawback. One nice feature was that the note title, date,
time, and author's name always appeared in the same place. After
using Notes for a while, your eye "knew" exactly where to look
for these things.
On the down side, each posting was limited to 20 lines of text so
as to fit on one screen. The only way to overcome this was to
write a series of responses, but that allowed other responders to
slip in and disrupt the flow. Still, the 20-line limit had the
virtue of encouraging brevity.
Most options for reading notes required only a single keypress.
While reading a response, for example, one keypress could perform
any of these functions (among others):
There were too many options to list them all on every screen.
Most prompts were quite minimal, but a Help key was universally
available. It would display a complete list of the options
available at any point.
- proceed to the next response
- go back to the previous response
- go back to the base note
- skip to the next base note
- begin writing a new response
Notes quickly became an indispensable part of the landscape. It
appeared just as PLATO was beginning a phenomenal growth spurt
made possible by the new mainframe. Although PLATO had been
evolving for over a decade by this time, to the new flood of
users coming on-line, PLATO without Notes was hard to imagine.
Copyright © 1994 by David R. Woolley
Copyright (c) 1996 - 2006 Elizabeth Mattijsen
I appreciate comments, suggestions and bug-reports.
Please send these to email@example.com.