Pegasus Computer

Behind the computer operator's head is a paper tape reader.
She is looking at a teleprinter,
and to the right of that is the paper tape punch.
In front of her is the programmer's switches
and above that the monitoring panel with two cathode ray tubes.
There were switches underneath to select what internal data
to display on the tubes, in binary - of course!

Just to give you some idea of the power of this 1956 computer:
The main storage was a drum having 40 fixed heads so 40 tracks.
Each track stored 128 words
Each word was 39bits
So the main store was 25KBytes in modern units.
The drum rotated at 3720 r.p.m. which is every 16 milliseconds.
So the average access time was 8 milliseconds.

The central processor used 55 registers plus some others,
These registers were "nickel wire delay lines"
Each of which stored one word - 39 bits.
Available every 0.126 milliseconds.
That is about 8000 cycles/second.
So this is the speed of the computer.
Even worse news is that the instructions it could obey
were much simpler/cruder/basic than later computers.
But in its time it was a wonder of its time.

Back to 5 Hole Paper Tape.