In the sixties, the IBM time-sharing system CP-67† would physically punch an "accounting card" on one of its card punches whenever a user logged off or did some

In the sixties, the IBM time-sharing system CP-67† would physically punch an "accounting card" on one of its card punches whenever a user logged off or did some other billable event, such as printing a listing. CP-67 ran on the 360/67, which was a 360/65 with special DAT hardware that allowed it to provide each user with their own virtual machine with its own address space. †http://www.multicians.org/thvv/360-67.html http://www.multicians.org/thvv/360-67.html