program patch panel plugboard program memory electrical computing computer computers
Early computing machines executed the set sequence of steps, known as a 'program', that could be altered by changing electrical connections using switches or a patch panel (or plugboard). However, this process of 'reprogramming' was often difficult and time-consuming, requiring engineers to create flowcharts and physically re-wire the machines. Stored-program computers, by contrast, were designed to store a set of instructions (a program), in memory – typically the same memory as stored data.
