In the last years of the nineteen-eighties, I worked not at startups but at what might be called finish-downs. Tech companies that were dying would hire temps—college students and new graduates—to do what little was left of the work of the employees they’d laid off. This was in Cambridge, near M.I.T. I’d type users’ manuals, save them onto 5.25-inch floppy disks, and send them to a line printer that yammered like a set of prank-shop chatter teeth, but, by the time the last perforated page coiled out of it, the equipment whose functions those manuals explained had been discontinued.