Page Description Languages

Communication between a computer and a printer is very different today to what it was several years ago. Text was sent in ASCII along with simple character codes instructing bold, italic, condensed or enlarged type. Fonts consisted of those built into the printer, distinguished more often than not by a switch selecting serif or sans serif. Graphics were produced line by line, slowly and streakily. The one big advantage of ASCII-described text is that its transmission happens quickly and easily: if the electronic document contains a letter A, the ASCII code for an A is sent and the printer, recognising the code, prints an A. The big problem was that without careful planning, the printed letter rarely ended up in the same position it held on the screen. Worse, the entire process was device-dependent, and so unpredictable, with different printers offering different font shapes and sizes.