Early computer communications

When, 110 years after the first such machines came on line, the
need arose to address computers remotely, telegraphy was the obvious
way to do so. No one expected computers in the early 1950s to give
instant results; jobs were assembled in batches, often fed in by
means of paper-tape (another borrowing from telex, still in use) and

then run. The instant calculation and collation of data was then
considered quite miraculous. So the first use of data communications
was almost exclusively to ensure that the machine was fed with
up-to-date information, not for the machine to send the results out
to those who might want it; they could wait for the 'print-out' in
due course, borne to them with considerable solemnity by the computer
experts. Typical communications speeds were 50 or 75 baud. (The baud
is the measure of speed of data transmission: specifically, it refers
to the number of signal level changes per second and is thus not the
same as bits-per-second.)
These early computers were, of course, in today's jargon,
single-user/single-task; programs were fed by direct machine coding.
Gradually, over the next 15 years, computers spawned multi-user
capabilities by means of time-sharing techniques, and their human
interface became more 'user-friendly'.

With these facilities grew the demand for remote access to
computers, and modern data communications began.
Even at the very end of the 1960s when I had my own very first
encounter with a computer, the links with telegraphy were still
obvious. As a result of happenstance, I was in a Government-run
research facility to the south-west of London, and the program I was
to use was located on a computer just to the north of Central London;
I was sat down in front of a battered teletype--capitals and figures
only, and requiring not inconsiderable physical force from my
smallish fingers to actuate the keys of my choice. As it was a
teletype outputting on to a paper roll, mistakes could not as readily
be erased as on a VDU, and since the sole form of error reporting
consisted of a solitary ?, the episode was more frustrating than
thrilling. VDUs and good keyboards were then far too expensive for
'ordinary' use.