Large and impressive print drum from a Burroughs 220 printer, measuring 17 1/2″ across with a 3 3/8″ diameter, and weighing 27.4 pounds. It was the key and most expensive field-replaceable component from the Burroughs 220 series mainframe. It represents early and crude attempts to solve bottleneck problems created by outputting data to a printer. This printer was considered the pace setter and became a landmark in the development of output devices. Some of the specifications for the Burroughs 220 line printer are impressive even by today’s standards: It was capable of printing an incredible 1,500 lines per minute in all numeric mode and 1,225 lines per minute in alpha-numeric mode—nearly 23 pages per minute! The drum has 120 characters across which are in capital letters and in reverse. The drum is completely covered in alpha-numeric characters which spiral around its circumference. 120 differently positioned hammers would spring out and impact the characters on the drum when they passed by at 1,800 RPM. It appears to be made of tempered steel and was built to last a lifetime. The original patina—dried ink and all—has been left intact. It is a fascinating sculptural piece of computing history.
