One afternoon the vice president of our toxicology department called me into his office to take a look at some mysterious printing problems he was having with the department’s computer. Documents suddenly stopped printing in mid-sentence, or vanished entirely between computer and printer. And often when this happened, the entire computer system had to be shut down and started before printing could resume.
The problem wasn’t hard to find. The department’s system consisted of a number of line switching devices, a 512K buffer, and a lot of cables. All of this equipment was in place to allow three personal computers to share three printers (a Hewlett-Packard Laser Jet, an IBM Quietwriter, and a dot matrix printer).
Whenever someone wanted to change the print destination, they had to get up from the terminal they were using, set the appropriate switches, send a test print, and cross their fingers. Not only was ...
