Memory access, Basic Computer Science

Assignment Help:

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. 


Related Discussions:- Memory access

Operating system services, Operating system services: In this section ...

Operating system services: In this section we consider basic services supported by an operating system. There are many building blocks to be considered, not all of which will

Boolean expression, Problem 1. Obtain the truth table and a Boolean exp...

Problem 1. Obtain the truth table and a Boolean expression for the following conditions: x is 0 if any two of the three variables are 1. x is 1 for all other conditions.

The form is merely submitted if a user selects either red, Question (a)...

Question (a) What do we signifies by saying that HTTP is a stateless protocol? (b) Explain three ways of working around that statelessness issue (c) Explain with the help

The central processing unit (cpu), THE CENTRAL PROCESSING UNIT (CPU): T...

THE CENTRAL PROCESSING UNIT (CPU): The CPU is the heart of any computing system.  It executes the individual machine instructions, which make up a program. The CPU is formed fr

Database management, what is the sql command to List all the join condition...

what is the sql command to List all the join conditions or join paths (pairwise) existing between tables.

Computer architecture, #formular for calculating speed up factor fo super s...

#formular for calculating speed up factor fo super scalar architecture, super pipeline architecture and VLIW with m different functional units.

Magnetic media, what are the five precautions to be observed when handling ...

what are the five precautions to be observed when handling magnetic media?

CAI, What is CAI? Explain its pitfalls.

What is CAI? Explain its pitfalls.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd