1. Videos – Do you need to view them?
Since Chapter 4, System Unit, is a more technical chapter than the first three chapters. I recommend that you do watch the video clips. It is just another means of communicating the concepts within Chapter 4.
If the video clips take too long to download, you will just have to move on to the next slide.
As before, view this presentation in the Slide Show View to preserve any hyperlinks and animation.
I hope you find that my presentations help prepare you for the exams. Besides, a multi-media presentation like this takes a long time to create.
Levi Krein Associate Professor, CIS

3. Levi Krein Associate Professor, CIS
Let’s take a look inside of the box, Arr!
Drive bay(s)
Power supply
Sound card
Video card
Processor
Memory
CIS 101: Intro to Computers
Levi Krein Associate Professor, CIS

4. Levi Krein Associate Professor, CIS
What is the system unit?
Case that contains electronic components of the computer used to process data
Sometimes called the chassis
Levi Krein Associate Professor, CIS

5. What are common components inside the system unit?
Processor
Memory
Adapter cards
Sound card
Modem card
Video card
Network card
Ports
Drive bays
Power supply
Levi Krein Associate Professor, CIS

6. Levi Krein Associate Professor, CIS
Click to view the “How Stuff Works” Video
CPU
Memory
Expansion Cards
Levi Krein Associate Professor, CIS

7. Levi Krein Associate Professor, CIS
What is the motherboard?
processor chip
adapter cards
memory chips
memory slots
motherboard
Expansion slots for adapter cards
Main circuit board in system unit
Contains adapter cards, processor chips, and memory chips
Also called system board
Levi Krein Associate Professor, CIS

8. Check out the following terms at Webopedia.
Chip = A small piece of semiconducting material (usually silicon) on which an integrated circuit is embedded. A typical chip is less than ¼-square inches and can contain millions of electronic components (transistors - switch). Computers consist of many chips placed on electronic circuit boards. There are different types of chips. For example: CPU chips (also called microprocessors) contain an entire processing unit Memory (RAM) chips contain blank memory (ROM chips studied later).
Short CHIP video
Levi Krein Associate Professor, CIS

9. Levi Krein Associate Professor, CIS
What is a CPU chip?
Small piece of semi-conducting material on which integrated circuits are etched
Integrated circuits contain many microscopic pathways capable of carrying electrical current
Chips are packaged so they can be attached to a circuit board
pin grid array (PGA) package holds processor chips
Levi Krein Associate Professor, CIS

10. What is the Central Processing Unit - CPU
Also called the processor
Processor
Control Unit
Arithmetic Logic Unit (ALU)
Control Unit
Arithmetic Logic Unit (ALU)
Interprets and carries out basic instructions that operate a computer
Information Data Information
Control unit directs and coordinates operations in computer
Memory
Input Devices
Data
Information
Output Devices
Information Data Information
Arithmetic logic unit (ALU) performs arithmetic, comparison, and logical operations
Storage Devices

11. Levi Krein Associate Professor, CIS
What is a machine cycle?
Four operations of the CPU comprise a machine cycle
Step 1. Fetch Obtain program instruction or data item from memory
Processor
Control Unit
Memory
ALU
Step 2. Decode Translate instruction into commands
Step 4. Store Write result to memory
Step 3. Execute Carry out command
Levi Krein Associate Professor, CIS

12. Levi Krein Associate Professor, CIS
What is pipelining?
CPU begins fetching second instruction before completing machine cycle for first instruction
Results in faster processing
Levi Krein Associate Professor, CIS

13. What is a register?
Temporary high-speed storage area that holds data and instructions
All data must be represented in a register before it can be processed.
Stores location from where instruction was fetched
Stores instruction while it is being decoded
Stores data while ALU computes it
Stores results of calculation
Levi Krein Associate Professor, CIS

14. Registers – Located on the CPU
Levi Krein Associate Professor, CIS

15. What are multi-core processors?
A chip with two or more separate processors
A dual-core processor is a single chip that contains two separate processors
A quad-core processor is a single chip that contains four separate processors
Each processor on a multi-core chip generally runs at a slower clock speed, but the combined overall performance is greatly increased
View a multi-core processor video.
I recommend watching at least the first & last segments:
Overview & How It Works
Intel Video is well done!

16. What is the system clock?
Controls timing of all computer operations
Generates regular electronic pulses, or ticks, that set operating pace of components of system unit
Each tick is a clock cycle
Pace of system clock is clock speed
Most clock speeds are in the gigahertz (GHz) range (1 GHz = one billion ticks of system clock per second)
Frequently missed test item!
The system clock is but one item related to computer performance
Levi Krein Associate Professor, CIS

17. Levi Krein Associate Professor, CIS

18. Levi Krein Associate Professor, CIS
Moore's Law Video
In 1965, Intel co-founder Gordon Moore saw the future. His prediction, now popularly known as Moore's Law, states that the number of transistors on a chip doubles about every two years.
Levi Krein Associate Professor, CIS

19. Levi Krein Associate Professor, CIS
State-of-the-Art
For most users ?
Levi Krein Associate Professor, CIS

20. Levi Krein Associate Professor, CIS
Check Your Processor
Select My Computer
System Tasks; View System Information
How are chips made?
Levi Krein Associate Professor, CIS

21. What are heat sinks and heat pipes?
Heat sink—component with fins that cools the processor on desktop computers
heat sink fan
Heat pipes—smaller device for notebook computers
heat sink
Levi Krein Associate Professor, CIS

22. What is parallel processing?
Using multiple processors (could be hundreds or thousands of CPUs) simultaneously to execute a program faster
Requires special software to divide problem and bring results together
Control Processor
Processor 1
Memory
Processor 2
Memory
Processor 3
Memory
Processor…. 100s -1,000s
Memory
Results combined
A couple of examples of parallel processing in action.
Levi Krein Associate Professor, CIS

23. How do computers represent data?
Most computers are digital
Recognize only two discrete states: on or off
Use a binary system to represent the two states
Use Number system with two unique digits: 0 and 1, called bits (short for binary digits)
Millions of Microscopic transistors on a chip
Levi Krein Associate Professor, CIS
p Fig. 4-13

24. Levi Krein Associate Professor, CIS
What is a byte?
Eight bits grouped together as a unit
Provides enough different combinations of 0s and 1s to represent 256 individual characters
Numbers
Uppercase and lowercase letters
Punctuation marks
Levi Krein Associate Professor, CIS

25. Popular Coding Schemes for Data Representation
Western European languages
ASCII
American Standard Code for Information Interchange
7 bit code (128 characters)
PCs & Midrange servers
Most frequently used code in the world
EBCDIC
Extended Binary Coded Decimal Interchange Code
8 bit code (256 characters)
Mainframe & high-end servers
Asian languages (all languages)
UNICODE
16 bit code (65,000 characters)
Operating systems
Windows
MAC OS
Linux
Levi Krein Associate Professor, CIS

26. Levi Krein Associate Professor, CIS
End Chapter 4: Part 1 - CPU
Chapter 4 - Part 2
Memory
Levi Krein Associate Professor, CIS

27. Levi Krein Associate Professor, CIS
What is memory?
Seat #2B4
Seat #2B3
Electronic components that store instructions, data, and results (information)
Consists of one or more chips on motherboard or other circuit board
Each byte stored in unique location called an address, similar to seat numbers on a passenger train
Levi Krein Associate Professor, CIS

28. Levi Krein Associate Professor, CIS
How is memory measured?
By number of bytes available for storage
Current computers typically have 2 – 8 gigabytes of memory
Levi Krein Associate Professor, CIS

29. What is random access memory (RAM)?
Memory chips that can be read from and written to by processor
Also called main memory or primary storage
Most RAM is volatile, it is lost when computer’s power is turned off
The more RAM a computer has, the faster it responds
Levi Krein Associate Professor, CIS

30. What are three basic types of RAM chips?
Does not have to be re-energized as often; expensive
Most common type
Dynamic RAM (DRAM)
Used for special applications such as cache
Static RAM (SRAM)
Faster variations of DRAM are SDRAM and RDRAM
Synchronized to the System Clock
Faster and more reliable than DRAM chips
Rambus – faster than SDRAM; use pipelining techniques
Magnetoresistive RAM (MRAM)
Uses magnetic charges to store data instead of electric charges, such as those used in SRAM and DRAM technologies. MRAM will retain data even when the power is turned off .
Levi Krein Associate Professor, CIS

31. Where does memory reside?
dual inline memory module
Resides on small circuit board called memory module
RIMMs hold RDRAM chips
SIMM & DIMMs hold SDRAM chips
Memory slots on motherboard hold memory modules
memory chip
memory slot
Memory
Levi Krein Associate Professor, CIS

32. How much RAM does an application require?
Software package typically indicate the minimum RAM requirements
For optimal performance, you need more than minimum specifications
System Requirements
Windows® XP Home Edition/Professional
Intel Pentium processor at 233MHZ or higher
AMD K6 (Athlon Duron Family processor at 233MHZ or higher
64 MB of RAM
Levi Krein Associate Professor, CIS

33. Levi Krein Associate Professor, CIS
What is cache?
A portion of memory made of high-speed static RAM (SRAM) instead of the slower and cheaper dynamic RAM (DRAM) used for main memory.
Memory caching is effective because most programs access the same data or instructions over and over. By keeping as much of this information as possible in SRAM, the computer avoids accessing the slower DRAM.
Also called memory cache
Cache memory video
Levi Krein Associate Professor, CIS

34. What are the different kinds of cache memory?
L1 cache built into processor
L2 advanced transfer cache is slower than L1 cache, but much larger capacity; built directly on processor chip; when discussing cache, most users are referring to L2 cache
Advanced transfer cache significantly increases the performance of a computer
L3 cache is separate from processor chip on motherboard (L3 is only on computers that use L2 advanced transfer cache)
Levi Krein Associate Professor, CIS

35. What is Read Only Memory?
Read-only memory (ROM) refers to memory chips storing permanent data and instructions
Unlike main memory (RAM), ROM retains its contents even when the computer is turned off. ROM is referred to as being nonvolatile, whereas RAM is volatile.
Most personal computers contain a small amount of ROM that stores critical programs such as the program that boots the computer.
Firmware is software (programs or data) that has been written onto read-only memory (ROM).
A PROM (programmable read-only memory) chip is a blank ROM chip that can be written to permanently
EEPROM electrically erasable programmable read-only memory that can be erased by exposing it to an electrical charge.
Levi Krein Associate Professor, CIS

36. Levi Krein Associate Professor, CIS
What is flash memory?
A specific type of EEPROM that can be erased and updated/reprogrammed.
Used with many mobile devices:
The flash memory can be built into the device or on removable memory cards
PDAs, digital cameras, digital cellular phones, music players, digital voice recorders, pagers, and thumb drives
Levi Krein Associate Professor, CIS

37. Levi Krein Associate Professor, CIS
What is access time?
Amount of time it takes to locate, read, and transfer data from memory making it available for processing.
Very fast, measured in nanoseconds (ns), one billionth of a second
1 blink = 1/10 of a second = 10 million computer operations
Levi Krein Associate Professor, CIS

38. Levi Krein Associate Professor, CIS
End Chapter 4: Part 2 - Memory
Chapter 4 – Part 3
Expansion Slots
Adapter Cards
Ports
Buses
Levi Krein Associate Professor, CIS

39. Levi Krein Associate Professor, CIS
What is an adapter card?
Types of Adapter Cards
Also called an expansion card
A circuit board that enhances the computer system or provides connections to external devices called peripherals
Expansion cards fit into expansion slots
Removing expansion card
Levi Krein Associate Professor, CIS

40. Levi Krein Associate Professor, CIS
What is Plug and Play?
Refers to the ability of a computer system to automatically self-configure expansion boards and other devices
The user does not need to worry about setting switches, jumpers, and other configuration elements.
Levi Krein Associate Professor, CIS

41. What is removable flash memory?
A PC card adds memory, sound, modem, and other capabilities to notebook computers
A flash memory card allows users to transfer data from mobile devices to desktop computers
A USB flash drive for storage plugs into a USB port
Hot plugging allows you to insert and remove cards while the computer is running
Levi Krein Associate Professor, CIS

42. What are ports and connectors?
A port connects external devices to the system unit
There are many different types of ports
Connector device physically joins cable to peripheral
Available in one of two genders: male and female
Levi Krein Associate Professor, CIS

43. What are different types of ports and connectors on your computer?
Very popular!
Levi Krein Associate Professor, CIS
USB & Firewire

44. What are USB ports?
USB (universal serial bus) port can connect up to 127 different peripherals together with a single connector type
PCs typically have two , four or more USB ports on front or back of the system unit
A single USB port can be used to attach multiple peripherals in a daisy chain or
via a hub
Third USB device connects to second USB device, and so on
Second USB device connects to first USB device
First USB device connects to USB port on computer
Daisy Chain
Levi Krein Associate Professor, CIS

45. What are special-purpose ports?
Allow users to attach specialized peripherals (digital video cameras, color printers, scanners, disk drives, etc.) or transmit data to wireless devices
FireWire high speed port
40+ times faster than USB
MIDI (Musical Instrument Digital Interface) port
SCSI (small computer system interface) high speed port
IrDA (Infrared Data Association) line-of-sight port
BluetoothTM (wireless - short range radio waves) port
Wi-Fi is a wireless technology that provides high-speed Internet and networks connections
Digital cameras; USB & FireWire may replace all other ports! BIG trend!
In the office; keyboards, printers, etc.
Very popular
Levi Krein Associate Professor, CIS

46. Levi Krein Associate Professor, CIS
What is a bus?
When referring to a PC, it is a data path or channel (wires or circuit) that allows devices inside the computer to communicate with each other
System bus connects processor and RAM
Bus width determines number of bits transmitted at one time
Word size is the number of bits processor can interpret and execute at a given time
Levi Krein Associate Professor, CIS

47. Types of expansion buses?
Expansion slots connect to expansion buses Common types of expansion buses include:
PCI bus
PCI Express bus
Accelerated Graphics Port
USB and FireWire bus
PC Card bus

48. What is an expansion bus?
Allows the processor to communicate with peripherals
AGP = 3-D graphics
System Bus = high-speed; connects RAM to processor (not an expansion bus)
PCI (local bus) = connects high-speed devices (SCSI cards, hard drives, sound cards, network cards; 4X faster than ISA)
ISA = older bus technology,
rapidly becoming obsolete
Levi Krein Associate Professor, CIS

49. Levi Krein Associate Professor, CIS
What is a bay?
Open area inside system unit, the space is used to install additional equipment
Drive bays typically hold:
Disk drives
DVD/CD drives
Levi Krein Associate Professor, CIS

50. Putting It All Together
What are suggested processor, clock speed, and RAM requirements based on the needs of various types of users?
Intel Core 2 Duo or Intel Celeron Dual Core or AMD Sempron
Minimum RAM: 2 GB
Home
Intel Core 2 Quad or Intel Core 2 Extreme or AMD Athlon FX or AMD Athlon X2 Dual-Code
Small Office/ Home Office
Minimum RAM: 4 GB
Intel Core 2 Extreme or AMD Turion X2
Mobile
Buy one of these!
I prefer the
Core 2 Quad
Minimum: Core 2 Duo

51. Levi Krein Associate Professor, CIS
Chapter 4 Complete
Video - The Apple Macintosh now uses an Intel processor!
Levi Krein Associate Professor, CIS