programing for engineers theory ch 1

For alfaisal uni

Program:

•set of instructions that a computer follows to perform a task

–Commonly referred to as Software

Programmer:

•person who can design, create, and test computer programs

–Also known as software developer

•Hardware:

The physical devices that make up a computer

–Computer

is a system composed of several components that all work together

•Typical major components:

–Central processing unit

–Main memory

–Secondary storage devices

–Input and output devices

Central processing unit (CPU):

• the part of the computer that actually runs programs

–Most important component

–Without it, cannot run software

–Used to be a huge device

Microprocessors:

CPUs located on small chips

•Main memory:

where computer stores a program while program is running, and data used by the program

Secondary storage:

•can hold data for long periods of time

–Programs normally stored here and loaded to main memory when needed

Input

•data the computer collects from people and other devices

•Output:

data produced by the computer for other people or devices

–Can be text, image, audio, or bit stream

what does system software do

•programs that control and manage basic operations of a computer

–Operating system: controls operations of hardware components

–Utility Program: performs specific task to enhance computer operation or safeguard data

–Software development tools: used to create, modify, and test software programs

How Computers Store Data

•Byte: just enough memory to store letter or small number

–Divided into eight bits

–Bit: electrical component that can hold positive or negative charge, like on/off switch

–The on/off pattern of bits in a byte represents data stored in the byte

whata the •Byte size limits

they are are 0 and 255

– 0 = all bits off; 255 = all bits on

– To store larger number, use several bytes

what is the most important coding scheme

it is ascii

how are images stored

–To store images, each pixel is converted to a binary number representing the pixel’s color

what is the typica cpu cycle

–Fetch: read the next instruction from memory into CPU

–Decode: CPU decodes fetched instruction to determine which operation to perform

–Execute: perform the operation

how does assembly language work

this langauge uses uses short words (mnemonics) for instructions instead of binary numbers

–Easier for programmers to work with

what is an assembler

it translates assembly language to machine language for execution by CPU

is python an example of a low level or high level langauge

it is a high level due to its high abstraction

is binary considered as an example of a low-level or a high-level language?

its concederd a low-level language because it directly interacts with the CPU

what are keywords in the context of a high level language

keywords are predefined terms used in writing high level langauges one suhc example is print in python

what are operators in the context of programing

perform operations on data

–Example: math operators to perform arithmetic

syntax

it is a set of rules for writing code

•Statement:

individual instruction used in high-level language

what is a •Compiler:

it translates high-level language program into separate machine language program

Machine language program can be executed at any time

what is an •Interpreter:

it translates and executes instructions in high-level language program

–Used by Python language

–Interprets one instruction at a time

–No separate machine language program

Source code:

•statements written by programmer

–Syntax error: prevents code from being translated

The IDLE Programming Environment

•single program that provides tools to write, execute and test a program

–Automatically installed when Python language is installed

–Runs in interactive mode

–Has built-in text editor with features designed to help write Python programs