History (1962): NCR CRAM First Commercially Significant Bulk Storage Subsystem

This article comes from the Computer History Museum.

1962: Bulk storage systems add low-cost capacity
NCR CRAM was the “first commercially significant Bulk Storage Subsystem”

John Potter Three-dimensional selector and memory device patent figure

(U.S. Patent Office)

In 1957 Potter Instruments delivered to Univac three experimental Three-Dimensional Memory Devices designed by George Comstock that stored up to 2 million characters on removable strips of magnetic tape.

Beginning in the 1960s, several companies introduced commercial bulk storage systems to offer online access to more capacity.

NCR was the first company to incorporate bulk storage as an integral element of online inquiries. Introduced in 1962, the CRAM (Card Random Access Memory) system stored data on 14×3.25-inch mylar cards with magnetic recording tracks. Up to 16 units attached to an NCR 315 mainframe offered a capacity of 80 million characters.

Other early 1960s systems based on magnetic stripes included the IBM 2321 Data Cell (MARS) and RCA Magnetic Card File (MCF).

As part of its Stretch supercomputer program, IBM developed a magnetic tape subsystem that could read and write electronically at the rate of 1.5 million characters/second. Installed at the U.S. National Security Agency (NSA) in 1962, the IBM 7955 Tractor system held up to 650 sealed 1.75-inch tape cartridges stored in an automated tape library.

To replace printed document storage, IBM delivered the Model 1360 Photo-Digital Storage System to Lawrence Livermore National Labs, CA in 1967. The PDSS exposed, developed, and stored strips of photographic film holding up to one terabit of data in trays moved by a pneumatic robot for online access.

The IBM 3850 Mass Storage System (1974) moved data from cartridge to disk and back in small, bullet-shaped magnetic tape cartridges designed for helical recording.

The StorageTek 4400 Automated Cartridge System (1987) integrated industry standard tape drives and cartridges into a library. Modular, rotary-access silo libraries were configured and expanded to user requirements.