Comp233 – Computer Systems Organization and Assembly LanguageLesson 1&2
LESSON 1 – Introduction to Computer Systems
Definition of Terms
Computer – is an electronics device capable of manipulating data into information at great speed, and with high accuracy.
System – a system is a group of elements that work together to complete a certain task or to achieve a specific goal.
Elements of a Computer System
- Hardware – input, processing and output
- Software – operating systems and application software
- Peopleware – users, literates, and professional
Classification of Hardware
- Input – hardware that allows the user to communicate to the computer, ex. keyboard, mouse, scanner, etc.
- Processing – refers to the central processing unit which performs either arithmetic/logic operations or control the system. Arithmetic operations include all mathematical computations like Addition, Subtraction, Division, Multiplication; Logic Operations include comparisons like <,>, =, or bit operations like OR, NOT, NOR, AND, XOR, XNOR, etc.
- Output – output hardware allows the computer to communicate provide information to the user ex, monitor and printer.
Classification of Software
- Operating Systems – software that are required by the system to function (i.e. boot up) are called the operating systems, ex. Windows95,Windows Vista, Windows , etc.
- Application Software – are programs that are used by the user ex. MS-Word, Excel, PowerPoint, Games, etc.
Classification of Peopleware
- User – a user is someone who uses the computer system. S/he may not have the necessary technical background or knowledge on how the machine works.
- Literates – are users who have the necessary know-how regarding computer.
- Professionals – professionals are people who have in-depth training on computer systems, ex. Programmers, Analysts, Engineers, etc.
Basic Building Blocks of a Computer System
The basic building block of a computer system includes
- Input
- Processing
- Output
- Memory
Types of Memory
- ROM – Read Only Memory (PROM, EPROM, EEPROM, etc.)
- RAM – Random Access Memory (SRAM, DRAM, etc)
Classifications of a Computer System
- Microcomputer – laptops, desktops, PDA’s
- Minicomputers – servers
- Supercomputers – Pentagon, NASA
- Mainframes – computers "housed in a metal frame"
Bus Lines
- Address Bus
- Data Bus
- Control Bus
- LESSON 2 – Information Representation
Signed / -32768 / +32767 / -2147483648 / +2147483647
Unsigned / 0 / 65535 / 0 / 4294967295
Number Systems
- Binary – B2 - 0,1
- Octal – B8 - 0,1,2,3,4,5,6,7
- Decimal – B10 - 0,1,2,3,4,5,6,7,8,9
- Hexadecimal – B16 - 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F
Code Conversion
- Binary – Octal – Decimal – Hexadecimal
1a.To convert from binary to octal, group the binary digits into 3 (from the right), and use 4-2-1 to get the equivalent in octal.
4 2 1 4 2 1
Ex. 100012= 10 / 001 = 218
1b.To convert from binary to decimal, multiply each binary digit to powers of 2.
Ex. 100012
1x 20= 1
0x 21= 0
0x 22= 0
0x 23= 0
1x 24= 16
1710
1c.To convert from binary to hexadecimal, group the binary digits into 4 (from the right), and use 8-4-2-1 to get the equivalent value in hexadecimal.
84 2 1 8 4 2 1
Ex. 100012= 0001/ 0001 = 1116
- Octal – Binary – Decimal – Hexadecimal
2a.To convert from Octal to Binary, use 4-2-1 and convert each octal digit to 3-digit binary code.
Ex. 218
4 2 1 4 2 1
010 / 0012
2b.To convert from Octal to Decimal, multiply each Octal digit to powers of 8.
Ex. 178
7 x 80 = 7
1 x 81 = 8
1510
2c.To convert from Octal to Hexadecimal, first convert to binary by getting the 3-digit equivalent of each octal digit using the 4-2-1, then group the Binary digits into 4 and get the equivalent hexadecimal value using 8-4-2-1 code.
Ex. 518
4 2 1 4 2 1
101/ 0012
8 4 2 1 8 4 2 1
10/ 10012
2 516
- Hexadecimal – Binary – Octal – Decimal
3a.To convert from Hexadecimal to Binary, use 8-4-2-1 and convert each hexadecimal digit to 4-digit binary numbers.
Ex. 8A16
84 2 1 8 4 2 1
1000/ 10102
3b. To convert from Hexadecimal to octal, first, convert to Binary then group the binary digits into 3, use 4-2-1 to get the octal equivalent.
Ex. 8A16
8 4 2 1 8 4 2 1 4 2 1 4 2 1 4 2 1
1000/ 10102 10/ 001/ 0102
2 1 28
3c.To convert from Hexadecimal to Decimal, multiply each hexadecimal digit to the powers of 16.
Ex. ACE16
14 x 160 =14
12 x 161=192
10 x 162 =2560
276610
- Decimal – Binary – Octal - Hexadecimal
4a.To convert from Decimal to Binary, divide the number by 2, then continuously divide the remainder by 2 until remainder is 0 or 1. Record the remainder backwards.
Ex. 1010 to B2
10 / 2 = 5 remainder 0 10102
5 / 2 = 2 remainder 1
2 / 2 = 1 remainder 0
4b.To convert from Decimal to Octal, divide the number by 8, then continuously divide the remainder by 8 until the remainder is less than 8. Record the remainder backwards.
Ex. 10010 to B8
100 / 8 = 12 remainder 4 1448
12 / 8 = 1 remainder 4
4c.To convert from Decimal to Hexadecimal, divide the number by 16, then continuously divide the remainder by 16 until remainder is less than 16.
Ex. 10010 to B16
100 / 16 = 6 remainder 4 6416
Instructor: Ms. Solane DuqueCollege of Arts and Sciences
Computer Science Section