The Terminal

A teletype (teleprinter or TTY) is a electromechanical device which was used to send/receive messages over telegraph lines, it was essentially a typewriter controlled electromechanically.

You basically type on a teletype machine and it would print that on a paper attached to that machine whilst also sending the keypress signals over telegraph lines, after which the receiver's teletype machine would receive and print out the message on it's paper.

The early computers used these teletype machines for input and output. Interfacing them was as simple as typing a command and hitting carriage return, After which the computer would do the required processing and print the output to the paper attached to the machine.

This was called a command line interface (CLI) and this is where the term carriage return originates from in context of computers.

Back in the time processors were super expensive, thus these CLIs didn't have a processor of their own, rather they were connected to a central computer thus earning the name The Terminal.

Somewhere after 70s, when Televisions started to become mass produced, the printing mechanism of the CLI was replaced with a Video Display Unit (VDU).

The VDUs were just a bolt-on replacement of the printing-to-paper mechanism, and they simply emulated printing as displaying text on screen and are often called Glass Terminal or Glass TTY.

The early VDUs included the ADM-3A, VT52, but most notably The VT100 which was a "Smart Terminal" because it had the ability to process escape sequences which could control the cursor position and many other things.

Soon personal computers (PC) came into the market with IBM being first with their IBM PC which had a CLI and unlike Terminals these PCs had their own processor yet the term "Terminal" is still used to refer to CLI.

The IBM PC's lore is one of it's kinds, it's probably the reason why Microsoft is such a big company today & LowSpecGamer has made super lovely videos on the IBM PC Lore, Who really invented the PC? & The PC that finally defeated IBM.

If you've used a Terminal, it's most likely that you've used what's called a Terminal Emulator. It is a piece of software that basically emulates a Terminal or TTY.

Attributions

• [1]: ArnoldReinhold, CC BY-SA 3.0, via Wikimedia Commons.
• [2]: nn, Public domain, via Wikimedia Commons.
• [3]: Autopilot, CC BY-SA 3.0, via Wikimedia Commons.
• [4]: Ruben de Rijcke, CC BY 3.0, via Wikimedia Commons