Now THIS was the good old days..!
This is a Decwriter. It is a combination keyboard and printer, with a serial port which connected to a Modem, a 300 Baud modem, which then connected to an HP2000F Mainframe computer.
Programming was done in languages that included BASIC, COBOL and FORTAN (Basic was my favorite). The HP2000F was a "Time Sharing" computer that many people could use at once.
The best was placing multi-player Space War on it. It would PRINT "values" to describe a ship in space, such as SPEED COURSE BEARING RANGE. You could launch photon torpedoes or fire phasers etc. It was all played with numbers (Great for your imagination), and printed reports every 10 seconds or so to update the gameplay with the other players position in both 2D and 3D space. It was GREAT... I miss it!