Chapter 1

Question 1

What is a program?

Answer 1

Is a set of instruction a computer follows to perform a task, commonly referred as software.

Question 2

What is a programmer?

Answer 2

Person with the skills to design, create and test programs

Question 3

Hardware?

Answer 3

Refers to the physical devices, or components, the a computer is made of. A computer is a system of devices that all work together

Question 4

What are the components of a typical computer system?

Answer 4

Central processing unit (CPU) Main memory (RAM) Secondary storage devices Input devices Output devices

Question 5

CPU

Answer 5

When a computer is performing the task that a program tells it to do, we say the computer is running or executing the program. The central processing unit, is the part of a computer that actually runs the programs. CPU is the most important part because without it it can not run programs. Nowadays also know as microprocessor

Question 6

What is the main memory?

Answer 6

Think of it as the computers works area. This were the computer stores the program while is running, as well as the data that the program is working with. Commonly known as random access memory (RAM). It’s called this because the CPU is able to quickly access data store at any random location in RAM.

Question 7

Secondary storage device?

Answer 7

Is a type of memory that can hold data for long periods of time, even when there is no power to the computer. Programs are normally store in secondary memory and loaded loaded into main memory as needed. Most common is a disk drive

Question 8

Disk drives?

Answer 8

Stores data by magnetically encoding into a circular disk

Question 9

USB drives

Answer 9

Small devices that plugs into the computer USB (Universal Serial Bus) port and appears to the system as a disk drive.

Question 10

Optical drives

Answer 10

Such as CD and DVD are also use for data storage. These do not encode information magnetically, but is encoded as a series of pits on the disc surface. A laser is use to detect the pits and thus read the encoded data.

Question 11

Input devices

Answer 11

Input Is any data the computer collects from people and from other devices. The component that collects the data and sends it to the computer is called input device

Question 12

Output devices

Answer 12

Output Is any data that the computer produces for people or for other devices. The data is sent to an output device which formats and presents it.

Question 13

How computers store values?

Answer 13

Concept: All data that is store in a computer is converted to sequences of 0s and 1s. Computers memory is divided into tiny storage locations knows as bytes. One byte is only enough memory to store a letter or a small number Each byte is divide into eight smaller locations know as bits. Bits stand for binary digits. Bits are tiny electrical components that can hold either a positive or negative charge.

Question 14

How computers store number?

Answer 14

A bit can be use in a very limited way to represent numbers. Depending on whether the bit is turn on and off, it can be present one of two different values. In computer systems, a bit that is turn off represents the number zero in a bit that is turn on represents the number one. This corresponds perfectly to the binary number system. The position of each digits in the binary number has a value assign to it starting with the right most digit

Question 15

Number values of Binary code when storing numbers

Answer 15

Question 16

What happens when you reach the limits of a byte?

Answer 16

The values on one byte can only hold the numbers up to 255. When a number is bigger than 255, the computer puts together two bytes and that gives us 2¹⁵ which translate into values up to 65,535

Question 17

Storing characters

Answer 17

Any data must be store in a memory as a binary number. When a character is stored in memory, it is first converted to a numeric code. The numeric code is then store stored as a binary number

Question 18

ASCII

Answer 18

American Standard Code for Information Interchange. Is one of the most important coding schemes. It is a set of 128 numeric codes that represents the English letters, various punctuation marks, and other characters.

Question 19

Unicode

Answer 19

Is an extensive coding scheme that was created in 1990’s due to the limitations of ASCII which only had 128 English characters. Unicode is an extensive encoding scheme that it is compatible with ASCII, and can also represents the characters of many of the world’s languages.

Question 20

Advance number system

Answer 20

To stored negative and real number in the memory such as 3.147. The computer uses other techniques, for negative number the computer uses the two’s compliment, and real number are encoded in floating-point notation

Question 21

Other types of data

Answer 21

Computers are referred to as digital device. The term digital is any device that work in binary data. Pictures are compose of tiny dots called pixels. (the term pixel stands for picture element) images are converted to a numeric code that represents the pixel’s color. The numeric code is stored in memory as a binary number. Music is broken into small pieces called samples, each sample is converted into binary number, which can be store in the memory.

Question 22

How programs work?

Answer 22

CPU performs simple operations on pieces of data. The CPU does nothing on its own, however. It has to be told what to do, that is the purpose of the program. A machine language instructions exists for each operation that a CPU is capable of performing. The entire set of instructions that a CPU can execute is known as the CPU’s “instructions set”

Question 23

Where do programs stores?

Answer 23

Programs are store in the secondary memory and each time that the program need to be executed is copied to the main memory, so that the CPU can execute the program from the main memory.

Question 24

Fetch-decode-execute cycle

Answer 24

When CPU executes the instructions in a program runs this cycle for each instruction.

Question 25

Fetch

Answer 25

This first step is to fetch, or read, the next instruction from memory into CPU

Question 26

Decode

Answer 26

A machine language instruction is a binary number that represents a command that tells the CPU to perform an operation. In this step the CPU decode the instruction that was fetched from memory, to determine what operations it should perform.

Question 27

Execute

Answer 27

To execute or perform the operation.

Question 28

Assembly language

Answer 28

Uses short words that are known as mnemonics. For example: in assembly language, the mnemonic add typically means add numbers, mul typically means multiply number, mov typically means to move a value to a location in the memory. Is a low level language that requires the programmer to know how the CPU works to be able to write instructions on a program.

Question 29

Assembler

Answer 29

Is a program use to translate assembly language to machine language

Question 30

High level language

Answer 30

Allows you to create powerful and complex programs without knowing how the CPU works, and without writing large numbers of low level instructions.

Question 31

Key words or reserved words

Answer 31

Each language has its own set of words that the programmer must learn in order to use the language.

Question 32

Operators

Answer 32

Programming languages also have operators that perform various operations on data.

Question 33

Syntax

Answer 33

Which is a set of rules that must be strictly followed when writing a program. The syntax rules dictate how key words, operator, and various punctuations characters must be used in a program.

Question 34

Syntax errors

Answer 34

Is a mistake such as misspelled key word, a missing punctuation character, or the incorrect use of an operator

Question 35

Statements

Answer 35

The individual instructions that you use to write a program in a high level programming language. It can consist of key words, operator, punctuation, and other allowable programming elements, arrange in the proper sequence to perform an operation.

Question 36

Compliers

Answer 36

Is a program that translate a high level language program into a separate machine language program.

Question 37

Interpreter

Answer 37

Is a program that both translate and executes the instruction in a high level language program. As the interpreter reads each individual instruction in the program, it converts it to a machine language instruction and then immediately executes it.

Question 38

Note on interpreter and complier

Answer 38

A program that is complied generally executes faster than programs that are interpreted because a complied program is already translated entirely to machine language when it is executed. A program that is interpreted must be translated at the time it is executed.

Question 39

Source code or code

Answer 39

Statements that the programmer writes in a high level language.

Question 40

Integrated Development Environments

Answer 40

Most programmers use this specialized software packages, they include: •text editors that has specialized features to write statements in high level programming language • a complier or interpreter • useful tools for testing programs and locating errors

Question 41

Programs category

Answer 41

Programs generally fall into one of two categories: • System software that is a set of programs that control or enhance the operation of a computer. ( operating systems, utility programs, and software development programs) • Application software makes a computer useful for everyday tasks. (Word, Excel,

Question 42

Operating System

Answer 42

An OS is the most fundamental set of programs on a computer. The OS controls the internal operations of the computer’s hardware, manage all of the devices connected to the computer, allows data to be saved to and retrieved from storage devices, and allows other programs to run on the computer

Question 43

Utility program

Answer 43

Performs specialized task that enhances the computer’s operation or safeguards data. Ex virus scanners, file compression programs, backup programs

Question 44

Software development tools

Answer 44

Are programs that programmers use to create, modify, and test software. Ex assemblers, compliers, and interpreters