The development of the computer made it necessary to store information. In the 1950s, programs in machine language and data only required a few kilobytes – but the need for memory and storage capacity grew exponentially. Conversely, data carriers became smaller and smaller. Since the advent of digitalization, an increasing variety of media content is being saved digitally: images, texts, videos and sound. The amount of data worldwide has mushroomed and by 2025, the annual data volume is predicted to reach 175 billion terabytes.
Many digital storage media originated in other contexts. Punch cards and strips were used to control machines as early as the 18th century. Magnetic tapes, cassettes, CDs and DVDs were previously used for analog sound recording. Diskettes, hard drives and flash drives, on the other hand, are new developments for storing digital information. Currently, outsourcing storage space to servers is gaining ground: more than one-third of all Germans use cloud storage today.
Punch cards – The storage medium of early programming
Initially, in the middle of the 18th century, punch cards were used to automate mechanical processes such as the Jacquard weaving loom. During the U.S. Census of 1890, engineer Herman Hollerith used punch cards to save and count data on the population.
Since a single punch card can only store 80 bytes of information, many cards were required for data storage and programming. Sometimes they were punched by hand. Large computing centers processed stacks and stacks of punch cards. Today the technology is still used for specific applications such as time clocks and automatic parking systems.
Photograph; employee of Deutsche Post der GDR inserting a magnetic tape into an electronic data processing unit (EDVA) at the Organization and Computer Center (ORZ) of Deutsche Post der GDR in Berlin/East Germany. (11.12.1976) by Photographer: Tluste GünterMuseum for Communication Frankfurt, Museum Foundation Post and Telecommunication
Magnetic tape – From recording sound to processing data
Magnetic tape was the first storage media used for a variety of different purposes. For decades, it was standard for media content such as sound and film recordings.
A magnetic tape is a plastic ribbon with a layer of magnetized pigments. It has a long service life (minimum 30 years). Originally developed for sound, the technology was first used for data storage in 1951 – in conjunction with UNIVAC I.
The data deletion device – Storage and data protection
The implementation of the German Federal Data Protection Act in 1978 made it necessary to reliably delete personal data. The Robby-Bit is a data deletion device that removes data from magnetic tape in three seconds using an electromagnet.
Exchangeable disk stores – Data storage for companies
In the 1970s, exchangeable hard disk stacks replaced punch card and magnetic tape storage in mainframe computers. They had impressively high capacities. Their drives were the size of washing machines, making them too big and expensive for private use.
Datasettes – Magnetic tape for home use
Commodore launched the first Datasette for its C64 computer in 1982. It was a comparatively inexpensive storage medium. The Grundig CR100a data recorder is a device for recording and playing digital data on conventional compact cassettes.
The disadvantages of Datasettes were long charging times, sequential access to the stored data and a limited storage volume of 100 kB or, with a fast loader, 1 MB per 30 minutes of magnetic tape. They were only accepted by consumers until the alternatives became affordable. By the mid-1980s, diskettes had finally replaced them.
Diskettes – Storage becomes smaller
The first diskette was launched in 1969. It was 8 inches (20 cm) wide and had a capacity of 80 KB. Diskettes are magnetic storage media: the data are stored on a plastic disk coated with metal. They were also called “floppy disks” because they were soft and flexible.
Over time, diskettes became smaller and smaller but their memory volume increased. Later 8" diskettes and the special 5.25" diskettes developed for desktop computers reached up to 1.2 MB and the smaller 3.5" diskettes, which were easier to transport, could even store up to 1.4 MB.
The price of memory started plunging with the CD. As laser wavelengths became shorter and the pits more compact, their capacity increased. As of 1988, 700 MB of data could be burned onto a CD-R once and onto the CD-RWs launched in 1996 multiple times. Identical to CDs at first glance, DVDs increased capacity to 4.7 GB as of 1997. Blu-Ray technology (2002) could record even more data: 25 GB.
CDs – Inexpensive memory
A CD (compact disc) is made of polycarbonate plastic coated with a reflecting alloy whose composition varies with the type of CD (CD-ROM/-R/-RW). A spiral track is molded into the top of the polycarbonate layer, which can be scanned and read by a laser.
By 1982 CDs had rendered music digital. With increasing storage capacity and cheap production, DVDs and Blu-Ray revolutionized home entertainment. Thanks to easy reproduction, they became cheaper and cheaper; by the beginning of the 2000s, they were a popular advertising giveaway.
Personal Computer by unknown manufacturerMuseum for Communication Frankfurt, Museum Foundation Post and Telecommunication
Hard drives – Rising storage capacity
With capacities starting at 20 MB, hard drives conquered the private sector as of the mid-1980s. At that time there were more than 200 manufacturers, but only three remain in business today.
Notebook "Satellite C850-16R" by Toshiba Europa (I.E.) Ltd.Museum for Communication Frankfurt, Museum Foundation Post and Telecommunication
With a size of 2.5", today’s drives are much smaller and provide up to 18 TB of memory.
Flash memories – Portable memory
Cards with electronic flash memory were developed in 1987. They were initially used for multi media data. Their size, capacity and access time were impressive: multi-media cards and secure digital (SD) cards developed into the solid state drive (SSD) widely used today.
Flash or thumb drives (external flash memories) were available commercially as of 2000. They save data on a microchip. Compact and lightweight, they have a standard interface and can be used as mobile memory for many different data formats.
The cloud – Worldwide data storage
The cloud was developed at the beginning of the 2000s – originally to balance out server utilization. It is based on a worldwide network of server and data centers with enormous capacity. The cloud makes it possible to store enormous amounts of data quickly and easily.
The cloud simplifies the exchange of personal documents such as snapshots, music and videos. With remote data backup, it simplifies internal and external data exchange for companies. It is gradually replacing other storage media such as CDs, hard drives and flash drives. Security is both an advantage and a disadvantage of the cloud. Data are securely stored in data centers, but can become the target of cyber attacks.
After many years with physically present data carriers, we are now storing data without knowing exactly where and how it is stored. This gives the impression of intangibility.
The exhibition presents the development of digital mass storage media. The figures help visitors to compare sizes. This is a joint project of students at the Institute of History at Technical University of Darmstadt (TU Darmstadt) in cooperation with the Museum für Kommunikation in Frankfurt.
The creation of this exhibition was funded by “Digital gestütztes Lehren und Lernen in Hessen” (Digitally supported teaching and learning in Hesse), a project of the Hessian Ministry for Higher Education, Research and the Arts and the Center for Educational Development and Technology at TU Darmstadt in summer semester 2021.
Dr. Nora Thorade, TU Darmstadt and Dr. Tina Kubot, Museum für Kommunikation, supported by Lasse Stelzer, supervised the seminar.
Students: A. C. Arndt, R. Aurich, S. Custodis, T. Drebert, M. Fenderl, O. Fliehmann, J. D. Geiger, S. Gerhard, K. L. Krollik, S. Maiwald, M. Miltenberger, S. L. Otters, M. Reuter, L. Stelzer, H.-J. Walther, K. Weiler, C. Wenner and M. Zivkovic.