What did computers without screens do?

On 15 December 2015 at 01:31, Mike <tulsamike3434 at gmail.com> wrote: I'll jump in here - take the current microcontroller hobby segment. You have PIC, or AVR, or Propeller based setups which is used for all kind of things like programmed robots, model cars, drones and RC planes, home control, model trains, temperature- and humidity controlled garden greenhouses, chicken shed day/night door control, and numerous other uses. These things are computers, a Propeller, for example, is an 8-core 32-bit small computer all in one chip. Usually these things have no screen and no keyboard connected. So you program them by various other means, e.g. through a serial interface. For the programming part of it (or the preparation of what you load via the serial interface, or jtag or e.g. a flash or eeprom chip) you'll need something else, today that's usually a PC, but that's conceptually the same thing as in times past where you used a terminal or some device with a keyboard to prepare punched cards or paper tape.