The 1960s and 1970s were the era prior to the rise of home and micro computing, when small computers weighed as much as a fridge (before you added any peripherals to them) and large computers took up entire air conditioned offices. Mainframes cost millions of dollars, minicomputers tens of thousands at a time when the average weekly wage was closer to a hundred dollars. To access a computer you had to engage with the institutions that could afford to maintain them – large businesses and universities, and with their guardians – the programmers and system administrators who knew how to encode ideas as marks on punched cards for the computer to run.