History of Computer Memory
Random Access Memory

Basics of RAM


Let's start with the basic terminology of the types of RAM memory that most of us are familiar with:


There are two types of RAM:


RAM Photos:                                                                                



A good definition for you to remember, "Computer memory refers to the physical devices used to store data or programs (sequence of instructions) on a temporary or permanent basis for use in an electronic digital computer. Computers represent information in binary code, written as sequences of 0s and 1s. Each binary digit (or "bit") may be stored by any physical system that can be in either of two stable states, to represent 0 and 1. Such a system is called bistable." (Wikipedia, 2008).




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A Brief History of the Evolution of RAM Computer Memory


Let's focus on the major types of computer memory in history.





Photo - Early Vacuum Tube 1940- 1950:           1950-1960  



Photo- Early Drum Memory 1932                                 1950's IBM 650              


Magnetic Drum memory video:   http://www.youtube.com/watch?v=eIpoA7Ir9p8


                                    Photo - Jay Forrester 1951 files patent for Core Memory                  







Photo - 1947 First transistor           Photo - Jack Kilby, Integrated Circuit 1958                                


Do you see the evolution link?


 Please see this detailed chart. A History of Information Technology and Systems It gives a great timeline of the evolution of computer systems and storage devices.



Here is a link to How Ram Works: http://www.howstuffworks.com/ram.htm

Here is another link on How Computer Ram Works: http://www.articlesbase.com/hardware-articles/how-computer-ram-memory-works-716360.html


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Important Dates in Computer History:


1801   Joseph Marie Jacquard improved upon a textile loom by introducing a series of punch card paper templates, which allowed the loom to weave intricate patterns automatically.

1833   Charles Babbage constructs the first punch card machine with a memory store called the Analytical Engine . This machine used gears and levers and was programmed by punch cards.This difference engine could solve polynomial equations.

1932   Gustav Tauschek builds first drum memory.

1936   Konrad Zuse builds a mechanical calculator called the Z1.The Z1 was known as the world's first binary computer. Zuse focused on three major elements a calculating device should have.

  1. A control
  2. Memory
  3. Calculator

The Z1 had an electrical engine and was programmed by punch tape. The Z2 had electrical relays and was known as the first electro mechanical computer. The Z3 had micro sequencers and used film tape instead of punch cards.

1946   Mauchly and Eckert develop the Eniac I (Electro Numerical Integrator and Calculator). The Eniac weighed 30 tons! It used Vacuum tubes, relays and switches.

1947   Fredrick Viehe , An Wang and Kenneth Olsen independently invent the magnetic core memory.      

          Jay Forrester develops the magnetic random access coincident-current drum.

1951   First commercial computer, The Ferranti Mark I . It had a 256 40-bit main memory and magnetic tape storage.

1952   The Edvac computer is created with 1024 44-bit words of ultrasonic memory. The Eniac gets a core memory device.

1954    First mass production of the IBM 650 magnetic tape data storage drum. First commercial ferrite-core memory.

1961    IBM 1401 magnetic core memory series. First transistorized 64-bit memory computer with memory protection and interleaving.IBM 7030 Stretch 64-bit data word and 32/64-bit instruction word computer.

1962   Atlas virtual memory

1965    British computer scientist Maurice Wilkes develops the idea of a cache computer memory. First integrated circuit random access memory application based on Read Only Memory ROM.

1968    Data General launches the 32-kilobytes memory Nova. Analog and digital memory are integrated on one chip by Dedicated Current Source. Robert Dennard invents and patents his Dynamic Random Access Memory DRAM. 

1969    Intel creates a 1 Kilobyte RAM chip. (Core Killer)

1970   First generally available Dynamic RAM 256-bit programmable semiconductor memory chip, the Intel 1103i. MOS Dynamic RAM is invented.




Computer memory timeline links: http://inventors.about.com/od/rstartinventions/a/Ram.htm


More detailed timeline information: http://www.lodbrok.be/refpages/timeline.htm







Important Machines in History That Used Memory













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Different Types of Ram



We have covered RAM, SRAM and DRAM. There are other types of RAM with distinct properties and differences. Some types you may know, DDR RAM, EDO RAM etc. Here is a link to help you learn the differences of these types of RAM.










In conclusion, my main desire is to highlight major technology advancements in the history of RAM. Mary Bellis outlined the importance of the transistor as being crucial to the growth of electronic computing. I agree with her statements. I believe that the inventions by Forrester, Olsen, Wang and Veigh created the most reliable, efficient and cost effective electronic memory which became Random Access Memory. The Inventors.About.Com web article" History of Computer Memory", cites these inventors as being pivital in the creation of modern day computer memory. I agree with web articles findings.




Quiz Time ! 

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White, Ron.(2008).How Computers Work. 9th. IN: QUE Publishing 9. Print.


Bellis, Mary, NP, web. History of Computer Memory, Retrieved from About.Com Guide, Inventors.http://inventors.about.com/library/weekly/aa050298.htm.

Bellis, Mary, NP Web The History of Vacuum Tubes. Retrieved from http://inventors.about.com/od/uvstartinventions/a/Vacuum_tube.htm

Binary Code: Retrieved from Wikipedia.http://en.wikipedia.org/wiki/Binary_code.

Butler, Jeremy G.(1997) A History of Information Technology and Systems.Retrieved from www.tcf.ua.edu/AZ/ITHistoryOutline.htm

Computer Memory Timeline: Timeline-Help.Retrieved from http://www.timeline-help.com/computer-memory-timeline-3.html.

Computing Timeline: Retrieved from http://www.lodbrok.be/refpages/timeline.htm.    

How Computer Ram Works: Article Base.com, NP, Web 2005-2010.Retrieved from http://www.articlesbase.com/hardware-articles/how-computer-ram-memory-works-716360.html.

How Stuff Works-RAM: How Stuff Works Inc.(1998-2010). Retrieved fromhttp://www.howstuffworks.com/ram.htm.

Inventors of the Modern Computer: About.Com Guide, Inventors. NP, Web 10/1/2010 Retrieved from http://inventors.about.com/library/weekly/aa060998.htm.

Konrad Zuse- Introduction: Retrieved from http://user.cs.tu-berlin.de/~zuse/Konrad_Zuse/en/konrad_zuse.html.

Ram: Quin Street Inc. (2010). Retrieved from Webopedia, About Internet.Com,http://www.webopedia.com/TERM/R/RAM.html.

Random Access Memory: Wikipedia NP, Web Retrieved fromhttp://en.wikipedia.org/wiki/Random-access_memory.

The Babbage Engine: The Computer History Museum. NP,Retrieved from http://www.computerhistory.org/babbage/howitworks/.

The History of Computer Memory, About.com, Inventors. NP, Retrieved from http://inventors.about.com/library/weekly/aa060998.htm.  



1950's Early mechanical "Direct Access" Drum Memory Storage. You Tube Video. Retrieved from You Tube http://www.youtube.com/watch?v=eIpoA7Ir9p8. 



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