Programming Hardware

One aspect of systems programming is writing programs that actually control the computer hardware. Every computer contains peripheral devices to transfer data between the computer and the outside world. For example most computers are connected to terminals so that people can interact with the computer. Most computers capable of running Modula-2 are also connected to disks so that information can be stored for long periods of time. Most computers are connected to printers, and most larger computers have clocks so that they can keep track of time. Even simple computers, such as a computer controlling a microwave oven, has a small collection of switches and sensors used for input and a few actuators used for output.