section_path: Innovations/Data
section_name: Data
paragraph_text: Data
  
  The first developments for storing data were initially based on photographs, starting with microphotography in 1851 and then microform in the 1920s, with the ability to store documents on film, making them much more compact. Early information theory and Hamming codes were developed about 1950, but awaited technical innovations in data transmission and storage to be put to full use.
  
  Magnetic-core memory was developed from the research of Frederick W. Viehe in 1947 and An Wang at Harvard University in 1949. With the advent of the MOS transistor, MOS semiconductor memory was developed by John Schmidt at Fairchild Semiconductor in 1964. In 1967, Dawon Kahng and Simon Sze at Bell Labs described in 1967 how the floating gate of an MOS semiconductor device could be used for the cell of a reprogrammable ROM. Following the invention of flash memory by Fujio Masuoka at Toshiba in 1980, Toshiba commercialized NAND flash memory in 1987.
  
  Copper wire cables transmitting digital data connected computer terminals and peripherals to mainframes, and special message-sharing systems leading to email, were first developed in the 1960s. Independent computer-to-computer networking began with ARPANET in 1969. This expanded to become the Internet (coined in 1974). Access to the Internet improved with the invention of the World Wide Web in 1991. The capacity expansion from dense wave division multiplexing, optical amplification and optical networking in the mid-1990s led to record data transfer rates. By 2018, optical networks routinely delivered 30.4 terabits/s over a fiber optic pair, the data equivalent of 1.2 million simultaneous 4K HD video streams.
  
  MOSFET scaling, the rapid miniaturization of MOSFETs at a rate predicted by Moore's law, led to computers becoming smaller and more powerful, to the point where they could be carried. During the 1980s – 1990s, laptops were developed as a form of portable computer, and personal digital assistants (PDAs) could be used while standing or walking. Pagers, widely used by the 1980s, were largely replaced by mobile phones beginning in the late 1990s, providing mobile networking features to some computers. Now commonplace, this technology is extended to digital cameras and other wearable devices. Starting in the late 1990s, tablets and then smartphones combined and extended these abilities of computing, mobility, and information sharing. Metal–oxide–semiconductor (MOS) image sensors, which first began appearing in the late 1960s, led to the transition from analog to digital imaging, and from analog to digital cameras, during the 1980s–1990s. The most common image sensors are the charge-coupled device (CCD) sensor and the CMOS (complementary MOS) active-pixel sensor (CMOS sensor).
  
  Electronic paper, which has origins in the 1970s, allows digital information to appear as paper documents.