Magnetic drum computers of the 1950s

We were cataloging text materials recently at the Computer History Museum and came across documents describing some early computers from the 1950s. These machines were being sold during the time when “small” machines used magnetic drums as memory. A few years later this type of memory was replaced in the market with core memories.

The Elecom 120 computer was sold by Underwood. Its magnetic drum memory contained storage for 1000 words of memory with an access time of 20 milliseconds. Programs for the machine were written in machine language. The Elecom could also attach paper tape and magnetic tape devices.

Another machine from the same era was the National Cash Register model 102-D. It was similar to the Elecom and also used drum memory.

National Cash Register 102-D computer

DEC archiving project at the Computer History Museum

The Computer History Museum (Mountain View CA) recently completed a large archiving project that consisted mostly of documents and photos donated to the museum by the Digital Equipment Corporation (DEC), which was headquartered in Boston and existed as a company from about 1950 through about 1998. DEC was one of the computer giants of its day, second only to IBM.

Dick and Anna participated in the project for its entire duration, which was about two years. The project contributed 20,000┬ánew items to the museum’s database.

Table set up to do archiving in the Computer History Museum collection
Table set up to do archiving in the Computer History Museum collection
One of the photographs from the DEC collection: participants in a sales training class in the 1980s
One of the photographs from the DEC collection: participants in a sales training class in the 1980s