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The Hollerith Punch Card
http://en.wikipedia.org/wiki/Punched_cardThis machine made processing the punched card faster and easier. The card contained digital information represented with the presence/absence of holes in certain postitions. It was first used in the US during the 1890 elections. -
Drum memory (1932)
http://en.wikipedia.org/wiki/Drum_memoryDrum memory is an obsolete magnetic data storage device. It was invented by Gustav Tauschek in 1932 in Austria and was widely used in the 1950s and into the 1960s as computer memory. Some drum memories were also used as secondary storage. -
Delay line memory (1947)
http://en.wikipedia.org/wiki/Delay_line_memoryDelay line memory was a form of computer memory used on some of the earliest digital computers. Like many modern forms of electronic computer memory, delay line memory was a refreshable memory, but as opposed to modern random-access memory, delay line memory was sequential-access. -
William Tube
http://en.wikipedia.org/wiki/Williams_tubeThe Williams tube, better called the Williams-Kilburn tube (after inventors Freddie Williams and Tom Kilburn), Developed in 1946 and 1947, was a cathode ray tube used as a computer memory to electronically store binary data. -
Magentic-core memory
http://en.wikipedia.org/wiki/Magnetic-core_memoryMagnetic-core memory was the predominant form of random-access computer memory for 20 years (circa 1955–75). It uses tiny magnetic toroids (rings), the cores, through which wires are threaded to write and read information. Each core represents one bit of information. The cores can be magnetized in two different ways (clockwise or counterclockwise) and the bit stored in a core is zero or one depending on that core's magnetization direction. -
F-RAM
http://en.wikipedia.org/wiki/Ferroelectric_RAMFerroelectric random-access memory has similar contruction like DRAM but instead of a dielectric layer, it contains a thin ferroelectric film to achieve non-volatility. F-RAM retains its data memory when power is shut off or interrupted. F-RAM was proposed by a graduate student Dudley Allen Buck but the development began in late 1980s and work was done in 1991.F-RAM has extremely high endurance, ultra low power consumption , etc. but low storage density and high cost. -
Selectron tube (1953)
http://en.wikipedia.org/wiki/Selectron_tubeThe Selectron was an early form of digital computer memory developed by Jan A. Rajchman and his group at the Radio Corporation of America under the direction of Vladimir Zworykin, of television technology fame. The team was never able to produce a commercially viable form of Selectron before core memory became almost universal, and it remains practically unknown today. -
PROM
http://vi.wikipedia.org/wiki/PROM
Programmable read-only memory, was invented in 1956 by Wen Tsing Chow, is a form of digital memory where the setting of each bit is locked by a fuse or antifuse. Its first use was to store the targeting constants in the Atlas E/F ICBM's airborne digital computer. It's a one-time programmable memory.It frequently uses in video game consoles, mobile phones, RFID tags, implantable medical devices, HDMI... -
Plated wire memory
http://en.wikipedia.org/wiki/Plated_wire_memoryPlated wire memory is a variation of core memory developed by Bell Laboratories in 1957. Its primary advantage was that it could be machine-assembled, which potentially led to lower prices than the hand-assembled core. -
Thin-film memory
http://en.wikipedia.org/wiki/Thin-film_memoryIn 1962, the UNIVAC 1107, intended for the civilian marketplace, used thin-film memory only for its 128-word general register stack. Military computers, where cost was less of a concern, used larger amounts of thin-film memory. Thin film was also used in a number of high-speed computer projects, including the high-end of the IBM System/360 line, but general advances in core tended to keep pace. -
Semiconductor RAMs Serve High-speed Storage Needs
http://www.computerhistory.org/semiconductor/timeline/1966-RAM.htmlSemiconductor RAMs Serve High-speed Storage NeedsBipolar RAMs enter the computer market for high-performance scratchpad and cache memory applications. -
Twistor memory
http://en.wikipedia.org/wiki/Twistor_memoryTwistor is a form of computer memory formed by wrapping magnetic tape around a current-carrying wire. Operationally, twistor was very similar to core memory. Twistor could also be used to make ROM memories, including a re-programmable form known as piggyback twistor. Both forms were able to be manufactured using automated processes, which was expected to lead to much lower production costs than core-based systems. -
Random-access memory
http://en.wikipedia.org/wiki/Random-access_memoryRandom-access memory (RAM /ræm/) is a form of computer data storage. A random-access device allows stored data to be accessed directly in any random order. In contrast, other data storage media such as hard disks, CDs, DVDs and magnetic tape, as well as early primary memory types such as drum memory, read and write data only in a predetermined order, consecutively, because of mechanical design limitations. -
Schottky-Barrier Diode Doubles the Speed of TTL Memory & Logic
http://www.computerhistory.org/semiconductor/timeline/1969-Schottky.htmlDesign innovation enhances speed and lowers power consumption of the industry standard 64-bit TTL RAM architecture. -
PRAM
http://en.wikipedia.org/wiki/Parallel_random-access_machine
PRAM or Phase-change memory exploit the unique behavior of chalcogenide glass. In 1969, Charles Sie published a dissertation, at Iowa State University that both described and demonstrated the feasibility of a phase change memory device by integrating chalcogenide film with a diode array. PRAM is much faster than the common flash memory, from 500 to 1,000 times faster, and it also uses up to one half the power. -
Bubble Memory
http://en.wikipedia.org/wiki/Bubble_memoryBubble memory is a type of non-volatile computer memory that uses a thin film of a magnetic material to hold small magnetized areas, known as bubbles or domains, each storing one bit of data. The material is arranged to form a series of parallel tracks that the bubbles can move along under the action of an external magnetic field. -
MOS Dynamic RAM Competes with Magnetic Core Memory on Price
http://www.computerhistory.org/semiconductor/timeline/1970-DRAM.htmlThe Intel i1103 Dynamic RAM (DRAM) presents the first significant semiconductor challenge to magnetic cores as the primary form of computer memory. -
EPROM
http://en.wikipedia.org/wiki/EPROM
Erasable programmable read only memory was invented by Dov Frohman of Intel in 1971. EPROM can be erased by exposing it to strong ultraviolet light source. It has a small quartz window which admits UV light for erasure. Once you erase it, everything will be erased and you can't keep the old data. Old PC BIOS used EPROM. -
Reusable Programmable ROM Introduces Iterative Design Flexibility
http://www.computerhistory.org/semiconductor/timeline/1971-EPROM.htmlDov Froman’s ultra-violet light erasable ROM design offers an important design tool for the rapid development of microprocessor-based systems, called an erasable, programmable read-only-memory or EPROM. -
EEPROM
http://en.wikipedia.org/wiki/EEPROMBecause the EPROM is too expensive to make and it doesn't keep old data when erase, EPROM is replaced by EEPROM-Electrically Erasable Programmable Read-Only Memory. In 1978, George Perlegos at Intel developed the Intel 2816, which was built on earlier EPROM technology, but used a thin gate oxide layer so that the chip could erase its own bits without requiring a UV source. EEPROM can be programmed and erased electrically using field electron emission and you can edit data on it. -
MRAM
http://en.wikipedia.org/wiki/Magnetoresistive_random-access_memory
Magnetoresistive RAM is under development since European scientists (Albert Fert and Peter Grünberg) discovered the "giant magnetoresistive effect" in thin-film structures. MRAM stores data by magnetic storage elements. It has the same reading and writing principle as magnetic core memory. Advantages are high density, least expensive...
