1. Introduction to Computers
Lesson 4A
Introduction to Computers

2. Decimal Number System
Called base 10 because 10 symbols are available

3. Binary Number System
Computers function in base 2, or the binary number system, where there are only two values

4. Bit A combination of binary digit
The smallest possible unit of data a computer can recognize or use

5. Byte
A group of eight bits

6. Text Codes
EBCDIC
ASCII
Unicode

7. CPU
The CPU is the computer’s “brain” that manipulates data

8. CPU’s Two Basic Parts
Control unit
Arithmetic logic unit

9. Control Unit
Manages all the computer’s resources

10. Arithmetic Logic Unit
Performs the CPU’s arithmetic and logical operations

11. Machine Cycle
The completed series of steps the CPU takes to execute an instruction

12. Machine Cycle’s Two Cycles
Instruction cycle
Execution cycle

13. Instruction Cycle
Fetching
Decoding

14. Execution Cycle
Executing
Storing

15. Millions of Instructions Per Second (MIPS)
The CPU performance measurement

16. Pipelining Also called pipeline processing
The control unit begins a new machine cycle before the current cycle is completed

17. Memory
Allows the CPU to store and retrieve data quickly

18. Two Kinds of Memory Read-only memory (ROM): nonvolatile
Random-access memory (RAM): volatile

19. ROM
ROM always holds the same data, for example the computer’s start-up instructions

20. RAM RAM’s job is to hold programs and data while they are in use
RAM can change instantly

21. Other Kinds of RAM Dynamic RAM (DRAM) DRAM Variations
Static RAM (SRAM)

22. Factors Affecting Processing Speed
Registers
Memory and computing power
System clock
The bus
The databus
The address bus
Cache memory

23. Bus Types Industry standard architecture (ISA) bus Local bus
Peripheral component interconnect (PCI) bus
Accelerated Graphics Port (AGP) bus
Universal Serial Bus (USB)
IEEE 1394 (FireWire)

24. Data Transfer Rate The amount of data buses can transfer in a second
Measured in megabits per second (Mbps) or megabytes per second (MBps)

25. Cache memory
Speeds processing by storing frequently used data or instructions in its high-speed memory

26. Transforming Data Into Information
Lesson 4A
Transforming Data Into Information