Random-access memory, or RAM, is a form of electronic computer memory that can be read and changed in any order, used to hold a running program's working data and machine code; unlike direct-access media such as hard disks and magnetic tape, a random-access device can read or write data in almost the same time regardless of where in memory that data sits. An early form, the Williams tube developed at the University of Manchester, provided the storage medium for the first electronically stored program, run on the Manchester Baby computer, and IBM introduced the first monolithic semiconductor RAM, the 16-bit SP95 static RAM chip for its System/360 Model 95, in 1965. Intel's 1103, introduced in October 1970, was the first commercially successful dynamic RAM integrated circuit, and RAM built from continually shrinking semiconductor chips has remained the standard working memory of computers ever since.
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SignificanceThe Williams tube was the first practical form of random-access memory, able to read or write data in any order rather than only sequentially. 1 FAQs
What is the difference between SRAM and DRAM?
SRAM uses about six transistors per bit and is faster and costlier; DRAM uses one transistor and one capacitor and is cheaper.
The two main kinds of modern RAM store each bit differently. Static RAM, or SRAM, holds a bit in the state of a memory cell that typically uses six transistors. That makes it more expensive to produce, but it is generally faster and needs less static power, so it is often used as cache memory for the processor. Dynamic RAM, or DRAM, holds a bit with one transistor and one capacitor, which is cheaper to produce and is why DRAM is the predominant form of main memory in modern computers. Both kinds are volatile, so they lose their contents when power is removed.
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Source Robert H. Dennard (ETHW)
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Source Random-Access Memory (Wikipedia)Wikipedia contributors
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Source Robert H. Dennard (ETHW)
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1. Random-Access Memory (Wikipedia)
Wikipedia contributors, Wikimedia FoundationHistory section, DRAM paragraph
The first commercial DRAM IC chip, the 1K Intel 1103, was introduced in October 1970.
Lead paragraph, Williams tube
The first practical form of random-access memory was the Williams tube. It stored data as electrically charged spots on the face of a cathode-ray tube. Since the electron beam of the CRT could read and write the spots on the tube in any order, memory was random access.
- In Group: Computer Data Storage Devices and Media, lead states RAM is a form of electronic computer memory that can be read and changed in any order, used to store working data
In Field: Computer Engineering, Categories
Computer architecture
View the Source Robert H. Dennard (ETHW)
Associated With: Robert H. Dennard, Biography
His accomplishments include pioneering the dynamic RAM memory cell used in most computers today, and playing a key role in the development of the concept of MOSFET scaling.
Invented By: Robert H. Dennard, Biography
His accomplishments include pioneering the dynamic RAM memory cell used in most computers today, and playing a key role in the development of the concept of MOSFET scaling.
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