Memory access, Basic Computer Science

Memory access:

The use of semi-conductor memory elements (bistables) has been made possible by the use of large scale integrated circuits (LSI) which provide reliability, ease of application and good storage capacity per unit volume.  A disadvantage of such memories is that a power supply is needed to hold the information stored.  Batteries may be provided to prevent loss of memory in case of power failure.  This is not necessary for memories made up of ferrite cores. 

Typically, 15 elements are needed for one word, therefore for a 2,000 word RAM we would need 30,000 elements arranged in a three dimensional matrix.  Figure 12 shows a 9-word store, each word consisting of 3-bits. 

80_memory access.png

Computer Memory

If one wishes to read the word at address W5, the memory address register sends, by way of the X and Y drive and decode circuits, a 1-bit along wires X2 and Y2.  The contents of W5 are then read sequentially from least significant bit to most significant bit by the sense wire, which is connected to each of the 27 elements. 

As part of a general-purpose computer ROMs may be used to store information which is unchanged over most, if not all, of the operational life of the equipment.  If all the hardware of a computer is wired in using ROMs then we no longer have a general-purpose computer and hence have lost the inherent flexibility.  However, saving in circuitry results, and some degree of flexibility can be regained by having interchangeable ROMs mounted on printed circuit boards (PCB) which can be removed from and fitted to the computer. 

Posted Date: 9/13/2012 7:10:04 AM | Location : United States







Related Discussions:- Memory access, Assignment Help, Ask Question on Memory access, Get Answer, Expert's Help, Memory access Discussions

Write discussion on Memory access
Your posts are moderated
Related Questions
#questionexplain strategic mis categories in detail with illustration..

let me know if you can do this assignment and how long it takes

(iv) Suppose that the TCP entity receives a 1.5 megabyte file from the application layer and that the IP layer is willing to carry blocks of maximum size 1500 bytes. Calculate the

Question 1 Explain with an example the three kinds of relationships that are most important in object oriented modeling Question 2 Describe the Common Modeling techniques in

Code for Program to find the second highest number from a given array in Assembly Language by using NASM

#que1) Create telephone directory. • The heading should be 16-point Arial font in bold • The rest of the document should use 10-point font size • Other headings should use 10-point


Suppose you are designing a database for an art museum that owns a large volume of works of art. Each work of art is described by a unique item code, a title, a type, and a size. T

Problem 1 What is precedence of operators? How are expressions evaluated using precedences? Defining precedence of operators Explanation of how expressions are evaluat

THE SECOND GENERATION (1956-1965) This generation of computers were characterized by:     Considerable reduction in physical size     Increased reliability