IBM 1360
| Company type | Product |
|---|---|
| Industry | Computer data storage |
| Founded | 1960s |
| Founder | IBM |
| Headquarters | San Jose , United States |
| Products | Photo-Digital Storage System (PDSS) |
The IBM 1360 Photo-Digital Storage System (PDSS) represented an early online archival storage solution tailored for extensive data center applications and was distinguished as the first system engineered to accommodate a terabit of data (128 GB). Its storage medium consisted of rigid photographic film cards, roughly the size of index cards, which were individually accessed and read. Updates were implemented by duplicating the modified data onto new film cards. IBM produced only six units of the PDSS, including the initial prototype, before discontinuing this film-card technology in favor of alternative storage methods. A comparable commercial product from the late 1960s was the Foto-Mem FM 390.
Walnut
During the mid-1950s, IBM's San Jose laboratory received a contract from the CIA to create a system capable of retrieving large volumes of printed documents efficiently. The development team concentrated on a novel photographic film called Kalvar, which was intended for microfilm duplication through ultraviolet light exposure and heat in a continuous roll-to-roll process. The project, internally named "Walnut," sought to automate the replication of materials stored on Kalvar film.
In January 1958, IBM appointed Jack Kuehler to lead the project’s development. He discovered that Kalvar was unsuitable for long-term data preservation due to its chemical instability and emission of corrosive gases. Kuehler proposed substituting Kalvar with a more chemically stable diazo-based film, which required processing in a wet laboratory environment. To accommodate this change, he suggested automating the diazo film development process. The CIA approved this modification, resulting in the launch of an updated Walnut system in 1961 and its delivery in 1962.
At the heart of Walnut was a large cylindrical carousel known as the document store, which housed 200 small compartments or cells. Each cell contained 50 film strips, with each strip holding 99 images arranged in a 3x33 matrix. Consequently, one document store could hold up to 990,000 document images, and multiple stores—up to 100—could be combined to reach a total capacity of 99 million pages.
To access documents, users employed an independent system that searched keywords stored on an IBM 1405 hard disk drive to locate relevant documents. This system produced punched cards that were fed into Walnut, prompting it to retrieve and duplicate documents onto film strips. These strips were then developed and four images were transferred onto an aperture card. These aperture cards could be viewed using microfilm readers or used as negatives for producing full-size prints.
Cypress
Following the successful deployment of Walnut in 1961, IBM’s San Jose laboratory shifted focus to commercializing this technology under the project title "Cypress." The 1350 Photo Image Retrieval System served as a direct adaptation of Walnut for document storage purposes, whereas the 1360 Photo-Digital Storage System modified this technology for computer data storage applications. Both systems utilized photographic cards and automated film processing methods derived from Walnut but replaced diazo film with more durable silver halide films. Pneumatic mechanisms transported film cards among the developer, reader/copier units, and a larger storage repository. Development and delivery oversight were provided by Jack Harker.
At the same time, the United States Atomic Energy Commission required an online storage solution capable of handling one terabit for use with supercomputer simulations. IBM’s Thomas J. Watson Research Center proposed an optical disk-based system, while San Jose advocated for Cypress. Ultimately, Cypress secured a $2.1 million contract for two units—delivered to Lawrence Livermore National Laboratory in September 1967 and Lawrence Berkeley National Laboratory in March 1968—with three additional systems later supplied to the National Security Agency and Los Alamos National Laboratory. These installations remained operational well into the late 1970s; IBM discontinued support and shut down the final unit in 1980.
The Cypress series constituted IBM’s sole deliveries under this initiative. By that time, IBM had introduced other storage technologies such as the IBM 3850, which it began promoting over the 1360 despite its greater sensitivity to environmental factors. End users generally favored the optical film technology of the 1360 for its superior reliability.
The IBM 1350 did not enter commercial sales. A "controlled marketing program" initiated in 1966 indicated that additional development was necessary, resulting in IBM halting its commercial introduction after only one year on the market.
Description
Information was recorded onto rigid film cards measuring 35 by 70 mm, known as chips, each containing 32 data frames arranged in a 4 by 8 grid. Every frame consisted of 492 lines with approximately 420 bits per line, encoded through Manchester encoding. Each chip held roughly 6.6 megabits of data. These chips were grouped into plastic containers called cells, each housing 32 chips. For shipment, ten cells were stacked together and wrapped before being loaded into a hopper on the 1365 Photo-Digital Recorder device, which managed the sequencing and feeding of cells for processing.
The writing process employed an electron gun akin to those used in television tubes. This gun featured eight filaments that rotated automatically to enable prolonged operation. Following exposure, the chips were subjected to automated photo development involving liquid chemical stations for processing and drying.
To compensate for imperfections in the film, sophisticated error correction codes were applied, consuming about 30% of the storage capacity and leaving approximately 4.7 megabits of usable data per chip. These error correction mechanisms addressed minor defects effectively. Once developed, chips were immediately evaluated by the 1364 Photo-Digital Reader. Any defective chips identified during this stage were discarded and replaced while the data still resided in memory.
During reading, chips moved past a stationary photocell in a boustrophedonic scanning pattern—alternating between left-to-right and right-to-left across rows—to enhance access efficiency.
After processing, chips were returned to their respective cells and transferred to either the 1361 Cell File & Control unit or the storage-only 1352 Cell File units. Each file unit contained 75 trays arranged in a 5x5x3 configuration, with each tray holding 30 cells, resulting in a total capacity of 2,250 cells or about half a terabit of data. The Lawrence Livermore installation utilized one 1361 and one 1352 unit to achieve a total capacity of one terabit; other deployments incorporated additional 1352 units to expand storage up to two terabits. Cells could be manually repositioned within trays for organizational flexibility.
Data writing speed was approximately 500 kilobits per second, while reading occurred at roughly 2.5 megabits per second. Movement of cells between file units and readers was facilitated by a pneumatic tube system capable of transporting up to thirteen cells simultaneously to minimize latency.
A dedicated small computer controlled overall system operations, executing fixed routines and converting data formats for host compatibility. IBM provided the 1367 Data Controller specifically optimized for Control Data Corporation platforms, reflecting common customer environments; alternative controllers supported different host systems.
Bibliography
- J. D. Kuehler and H. Ray Kerby, "A photo-digital mass storage system", Proceedings of the November 7–10, 1966, fall joint computer conference, American Federation of Information Processing Societies, 1966, pp. 735–742
- Gilbert King, "Data Processing with the Photostore," Chap. 19 of "Large Capacity Memory Techniques for Computing Systems," Macmillan, New York, 1962, pp. 301–304
- Robert Potter, "Component Evaluation for an Optical Data Processor," Optical Processing of Information, Spartan Books, 1963, pp. 168–186. Covers the IBM Photostore in the AN/GSQ-16.