CIS 251 – Lesson 2CIS 251 – Lesson 2

Essential Computer ConceptsEssential Computer ConceptsRod RodriguesRod Rodrigues

Types of Computers Types of Computers

Personal Computers or PCsPersonal Computers or PCs

Handheld Computer or PDAHandheld Computer or PDA

Large Business ComputersLarge Business Computers– MidrangeMidrange– MainframeMainframe– SupercomputerSupercomputer

InterfaceInterface

An Interface is the way in which the An Interface is the way in which the computer’s basic system interacts computer’s basic system interacts with the user. with the user.

Mainframe text-basedMainframe text-based– copy myfile.bas f:\copy myfile.bas f:\

Windows or Mac GUIWindows or Mac GUI– Click and drag filesClick and drag files

How Computers Represent DataHow Computers Represent Data

In order for information to In order for information to flow through a computer flow through a computer system in a form suitable system in a form suitable for processing all symbols, for processing all symbols, pictures or words must be pictures or words must be reduced to a string of reduced to a string of binary digits.binary digits.

bytes

bits

ASCII Code and UnicodeASCII Code and UnicodeThese are mappings between binary These are mappings between binary codes and characters of the codes and characters of the alphabets of different languages.alphabets of different languages.the the ASCIIASCII code for “A” is 65, code for “A” is 65, or 1000001or 1000001Chinese: over 2,000 symbols.Chinese: over 2,000 symbols.Unicode blows the lid off of the ability Unicode blows the lid off of the ability to represent World Languages by to represent World Languages by computer. computer.

A Typical SystemA Typical System

CPUs and MicroprocessorsCPUs and Microprocessors

Microprocessors integrate all of the Microprocessors integrate all of the memory, logic and control circuits for memory, logic and control circuits for an entire CPU on a single chipan entire CPU on a single chip

ROMROM

Volatile StorageVolatile StorageRAM storage has three functionsRAM storage has three functions– Stores all or part of the program that is being Stores all or part of the program that is being

executedexecuted– Stores the operating system programs that Stores the operating system programs that

manage the operation of the computermanage the operation of the computer– Holds the data that the program is usingHolds the data that the program is using

Secondary StorageSecondary Storage

Floppy Disks Floppy Disks or diskettes, or diskettes, Hard disk, ZIP Hard disk, ZIP disk, CDs (CD, disk, CDs (CD, CD-R, CD-RW, CD-R, CD-RW, DVD, DVD-R, DVD, DVD-R, DVD-RW, USB DVD-RW, USB drivedrive

Magnetic TapeMagnetic TapeAn older storage technology that is still employed An older storage technology that is still employed for secondary storage of large volumes of for secondary storage of large volumes of informationinformation

Olderreel-to-reel

Data CommunicationsData Communications

The transmission of text, numeric, The transmission of text, numeric, voice, or video data from one voice, or video data from one computer to anothercomputer to another

Protocol is a set of rules, or languageProtocol is a set of rules, or language

Analog and DigitalAnalog and Digital

ModemModem

NetworkingNetworking

Computer SoftwareComputer Software

System SoftwareSystem Software

Application SoftwareApplication Software

A ReminderA ReminderWebCTWebCT– All email should occur through WebCTAll email should occur through WebCT

Email me using WebCT and NOT my school or Email me using WebCT and NOT my school or home email addresshome email addressI will ALWAYS email you through WebCTI will ALWAYS email you through WebCT

– ONLY IF WEBCT is NOT FUNCTIONING, may ONLY IF WEBCT is NOT FUNCTIONING, may you email me using you email me using mrodrigues@ric.edumrodrigues@ric.edu and I will use the email address you and I will use the email address you supplied when you signed up for WebCTsupplied when you signed up for WebCT

– Logon to WebCT to check for Logon to WebCT to check for announcements and email DAILYannouncements and email DAILY

The EndThe End

http://http://www.ric.eduwww.ric.edu/mrodrigues/mrodrigues