Chapter 1Data Storage(2)

Yonsei University

1st Semester, 2014 Sanghyun Park

Outline Bits and their storage (prev. file) Main memory (prev. file) Mass storage Representing information as bit patterns Binary system Storing integers (next file) Storing fractions (next file)

Mass Storage Systems Non-volatile; data _______ when power is off

Usually much ______ than main memory

Usually _______ disks Hard disk, floppy disk, CD-ROM Much ______ than main memory because

(1) data access must wait for _____ time (head positioning), and(2) data access must wait for ________ latency

Disk Storage

CD Storage

Magnetic Tape Storage

Representing Text ASCII (adopted by American National Standards Institute

ANSI) American Standard Code for Information Interchange _____ to represent each symbol Upper and lower case letters of English alphabet,

punctuation symbols, digits 0 to 9, and other symbols Can represent 256 (28) different symbols

Unicode _____ to represent each symbol Can represent 65,536 (216) different symbols

ISO (International Organization for Standardization) _____ to represent each symbol Can represent more than 17 million symbols

Representing Numeric Values Binary notation –

uses bits to represent a number in base ____

Limitationsof computer representations of numeric values ________ happens when a number is too big to be represented _________ happens when a number is between two

representable numbers

Representing Images Bitmap techniques

Image is a collection of ______ (picture element) Each pixel can be represented as a number of bits

1 bit/pixel Black and white8 bits/pixel Gray scale24 bits/pixel 1-byte for each of the primary colors RGB

Size? (need for ___________)

Vector techniques Image represented as collection of _____ and curves Fonts on printers _______ fonts (True Type, PostScript) CAD (Computer Aided Design) _______ problem

Representing Sound

Base Ten and Base Two Systems

Decoding the Binary Representation

Finding Binary Representation ofPositive Integers

Finding Binary Representationof Thirteen

Binary Addition Facts

Fractions in Binary (1/3) Use _____ point just like decimal To the _____ of radix point positions are numbered

as -1, -2, -3, …

Fractions in Binary (2/3) Express the following binary notation

Convert the integer part Convert the fraction part;

Try to map the fraction as a sum of ___________________using the given ___________ as a guide.

Put a radix point in between

1653

310 is 112

20101.041

161

164

161

165

20101.111653

Fractions in Binary (3/3) Addition of binary numbers with radix points

_____ radix point Apply binary addition process

0010.011

+ 100.110

0111.001