The history of computers goes back to ancient Greece, with the Ankithera machine that was an Astronomical calculator to compute the positions of the planets. More recently, Blaise Pascal (1623 – 1662) of France invented the computing machine to perform various calculations which were followed by Gottfried Wilhelm Leibniz (1646 – 1716) of Germany and the arguably most famous of all, Charles Babbage (1792 – 1871) of England. Who built the difference engine to perform calculations and output the results with the positions of gears and input the data mechanically to program the machine. Charles Babbage envisioned a machine that could output on paper that would be able to save a hard copy of the data. This would allow transcribing errors to be eliminated with proofreading. The way each machine worked improved as each was invented, Pascal’s machine was built to follow only the addition algorithm. Consequently, the appropriate sequence of steps was embedded in the structure of the machine itself. In a similar fashion, Leibniz’s machine also had its algorithms embedded in its structure. However, Leibniz’s machine offered a variety of arithmetic operations from which the operator could select. Finally, Babbage’s machine allowed the user to use punched cards to program a sequence of steps the machine was to perform into the machine and have a stockpile of ready programmed cards ready to hand to perform any calculation desired. The idea of punched cards goes back to 1801, Joseph Jacquard had used a similar technique for controlling weaving looms in France. These machines are considered algorithmic machines versus numeric calculators and are not normally mentioned in computing history.
The real computing age really began when the Mark 1 computer was built in 1944, using electronically controlled relays. This was an electromechanical computer not a fully solid-state computer like the ones we have now. And it took up a whole room, like the ENIAC (Electronic Numerical Calculator And Computer) which used vacuum tubes instead of modern Transistors to perform calculations. This was the first fully electronic computer to be built, then the invention of the transistor allowed even smaller machines to be built with significantly more computing power than the Mark 1 which would fit in a box on a desktop. The 8086 computer seems pretty slow these days, but it was the fastest machine of its time in 1978, the year I was born! The Tandy 1000 desktop computer was the first desktop machine I really used, before that, I had used a computer with a cassette tape drive to load programs off music cassettes tapes. They were fun when you played them in an audiotape player. The Tandy 1000 runs at 4.77 Megahertz. That is a beast. You could plug a TV screen into the composite input and use a TV as a monitor although the picture quality would not be as good. I remember that my dad was using an older version of a Tandy computer on his machine and I could tune in the TV in my room across the house and see what he was working on.
I have heard about monitoring what is on a CRT screen in a modern machine by capturing the radiation emitted from the screen. But if you have an underground hacking dungeon with an earthed copper faraday cage then you will be safe. Or a TFT/LCD screen. If you have a device to enable TEMPEST snooping then you can read monitor displays at 300 yards range by re-constructing the screen from the electromagnetic emissions from the screen. This is elite black hat stuff used by the government to snoop on people from a distance. There is also Van Eck phreaking, this is viewing the contents of a video monitor remotely using a radio receiver, this apparently can work on TFT monitors as well. Here is a paper concerning this attack.
https://www.cl.cam.ac.uk/~mgk25/pet2004-fpd.pdf. Electromagnetic Eavesdropping Risks of
Flat-Panel Displays.
I do wonder if this would work with an HDMI or Display Port connection, or is it the circuitry that actually displays the signal on the screen? I guess a high-security installation would not allow anyone to get close enough to manage this attack in the first place. It is not like you can just get a job as a greenskeeper to spy on the installation like in the movie Sneakers. it would not be that easy.