1. Using Information Technology
Chapter 4
Hardware--The CPU & Storage
To the instructor:
This presentation attempts to cover every term in the text, sometimes via a slide, sometimes via the Notes page.
Additional material beyond what is in the text is presented via:
Occasional “FACTOID” notations on the Notes page, and;
Occasional hyperlinks in the slides themselves. ScreenTip text has been added to each hyperlink allowing you to see in advance of selecting the hyperlink where that link will take you.
In addition, the last ~20 slides are questions covering the material just presented. They can be used to increase interaction between the instructor and students at the end of each lecture, to ensure students understand the material just presented, etc.
Finally, some of the Notes pages include “Discussion questions” for use in encouraging student interaction during the lecture.

2. Hardware--The CPU & Storage How to Buy a Multimedia Computer System
4.1 Microchips, Miniaturization, & Mobility
4.2 The System Unit
4.3 Secondary Storage
Key Questions (from the text):
5.1: Microchips, Miniaturization, & Mobility. What are the differences between transistors, integrated circuits, chips, and microprocessors?
5.2 The System Unit. How is data represented in a computer; what are the components of the system cabinet; what are processing speeds; how do the processor and memory work; and what are some important ports, buses, and cards?
5.3 Secondary storage. What are the features of floppy disks, hard disks, optical disks, magnetic tape, smart cards, and online secondary storage?
5.4 Future Developments in Processing & Storage. What are some forthcoming developments that could affect processing power and storage capacity?

3. 1940s vacuum tube towering over 1950s transistor
4.1 Microchips, Miniaturization, & Mobility From Vacuum Tubes to Transistors to Microchips
Vacuum Tubes – 18,000 in ENIAC in Failed every 7 minutes, took 15 minutes to replace!
Transistor (1st was 1/100th size of vacuum tube) - a tiny electrically operated switch, or gate, that can alternate between “on” and “off” many millions of times per second
1960 – 1 transistor was ½ centimeter sq.
2003 – 3 million transistors on ½ cent sq.
Emphasize that today’s transistors are MICROSCOPIC in size.
Today, transistors are part of an…
Integrated circuit (IC) - an entire electronic circuit, including wires, formed on a single “chip,” or piece of special material, usually silicon.
IC production is an example of solid-state technology.
Solid state - electrons are traveling through solid material.
1940s vacuum tube towering over 1950s transistor

4. CHIP or MICROCHIP
A tiny piece of silicon (semiconductor) that contains millions of micro-miniature electronic components, mainly transistors. Silicon is found in sand.
Microprocessor: Miniaturized circuitry of a computer processor – the part that processes, or manipulates data into information

5. Steps in Manufacture of a Microchip
Make large drawing. Reduce drawing hundreds of times to microscopic size.
Duplicate reduced photo many times on sheet.
Print sheet of multiple copies on a wafer made of silicon, a semiconductor.
Print layer after layer above and below original silicon surface.
Cut wafer into chips.
Mount chip in frame with connective pins extruding.
[Note: THEN transistors were individually formed. Circuits attached w/wire & solder. TODAY integrated circuits & wires are formed together in a single chip.

6. 4.2 The System Unit The Binary System: Using On/Off Electrical States to Represent Data & Instructions
The binary system has only two digits--0 and 1.
Bit - binary digit
Byte - group of 8 bits used to represent one character, digit, or other value

7. The Binary System: Using On/Off Electrical States to Represent Data & Instructions
Kilobyte 1000 bytes
Megabyte 1,000,000 bytes (one million)
Gigabyte 1,000,000,000 bytes (one billion)
Terabyte 1 trillion bytes
Petabyte 1 quadrillion bytes
FACTOIDs:
The prefix “mega” in “megabyte” comes from the Greek word “megas” meaning “mighty” or “great.”
The prefix “giga” in “gigabyte” comes from a Greek word meaning “giant.”
The prefix “tera” in “terabyte” comes from a Greek word meaning “monster.”
You might think that the largest unit of storage capacity is a petabyte, but in fact, there are also exabytes, zetabytes, and yottabytes.

8. The Binary System: Using On/Off Electrical States to Represent Data & Instructions
ASCII (American Standard Code for Information Interchange) - the binary code most widely used with microcomputers
EBCDIC (Extended Binary Coded Decimal Interchange Code) - used with large computers
Unicode - uses two bytes for each character rather than one.
Instead of 256 character combinations of ASCII, 65,536 character combinations allow all languages to be represented.
Discussion question: How many possible different characters can Unicode represent and how is that derived?
Answer: 2 to the 16th power=65,526 character combinations

9. The Computer Case: Bays, Buttons & Boards
Bay - a shelf or opening used for the installation of electronic equipment
System unit - houses the motherboard, power supply, and storage devices
Case - empty box with just power supply
FACTOID: A bay which is open to the outside of the PC is termed “accessible” or “exposed.” A bay which is closed inside the PC case is termed “hidden” or “internal.”
Power supply - a device that converts AC to DC to run the computer.
Overhead view of system unit

10. The Motherboard & the Microprocessor Chip
Motherboard - the main circuit board in the system unit
Expansion - increasing a computer’s capabilities by adding hardware
Upgrading - changing to newer, more powerful versions

11. The Motherboard & the Microprocessor Chip
Two principal architectures or designs of microprocessors:
CISC (Complex Instruction Set Computing) - Supports a large number of instructions at relatively low processing speeds
RISC (Reduced Instruction Set Computing) - Supports a reduced number of instructions in order to obtain faster processing speeds
Two kinds of microprocessors used in most microcomputers today:
Intel-type chips for P/Cs made by Intel, AMD, and others (Pentium. The P4 has 42 million transistors)
Motorola-type chips made by Motorola for Apple Macintosh computers

12. The Motherboard & the Microprocessor Chip
MICROPROCESSOR – contains a system clock, which controls how fast all the operations within a computer takes place
System clock – uses fixed vibrations from a quartz crystal to deliver a steady stream of digital pulses or “ticks” to the CPU.
Ticks are called cycles
Faster clock speeds result in faster processing and execution of program instructions.
Steps in the machine cycle (Tick) [series of operations performed by control unit to execute a single programmed instruction]:
Fetch an instruction
Decode the instruction
Execute the instruction
Store the result
Microprocessor speed expressed in Megahertz, a frequency equivalent to 1 million cycles (ticks) per second. (1 GHz - 1 billion cycles per second)

13. How Processor or CPU works: Control Unit, ALU, & Registers
CPU – Central processing unit (Brain): consists of 2 parts (both contain registers, high speed storage areas).
2 parts are linked by electronic roadways “bus.”
Control unit – deciphers each instruction stored in it and carries out. Directs electrical signals bet main memory & ALU & input/output devices.
Arithmetic Logic Unit – ALU – performs arithmetic & logic operations (comparisons) & controls speed
Word size - the number of bits that the processor may process at any one time. The larger the word size, the faster the computer.

14. How Processor or CPU works: Control Unit, ALU, & Registers
BUS – bits are transmitted within the CPU and between CPU & other components of motherboard.
Word size - # of bits a processor may process at one time. 32-bit “word” microprocessor will transfer data w/in each processor chip in 32-bit chunks.
Word size - the number of bits that the processor may process at any one time. The larger the word size, the faster the computer.

15. How Memory Works: RAM, ROM, CMOS, & Flash
Types of memory chips:
RAM - Random Access Memory, used to temporarily hold software instructions & data in main memory (volatile)
ROM
CMOS
Flash
Volatile - a term used to describe memory in which the contents are lost when the power goes off or is turned off.
4 types of RAM chips:
DRAM – Dynamic RAM – must be constantly refreshed
SDRAM – Synchronous DRAM – Synchronized by system clock, goes faster
SRAM – Static RAM – doesn’t need to be refreshed, faster than DRAM

16. How Memory Works: RAM, ROM, CMOS, & Flash
Types of memory chips:
RAM
ROM - Read-Only Memory, which cannot be written on or erased by the computer user. Contains fixed start-up instructions
CMOS
Flash
Read - to transfer data from an input source into the computer’s memory or CPU.
Write - to transfer data from the computer’s CPU or memory to an output device.
FACTOID: “Firmware” is a combination of software and the read-only storage hardware (such as ROM chips) on which it is recorded.

17. How Memory Works: RAM, ROM, CMOS, & Flash
Types of memory chips:
RAM
ROM
CMOS - Complementary metal-oxide semiconductor; powered by a battery and thus doesn’t lose its contents when the power is off (non volatile)
Flash
CMOS chips are used to store items such as time, date, and calendar, that must be kept current even when the power is turned off.

18. How Memory Works: RAM, ROM, CMOS, & Flash
Types of memory chips:
RAM
ROM
CMOS
Flash memory chips – to store program - can be erased and reprogrammed more than once (non volatile)

19. How Cache Works: Level 1 (Internal) & Level 2 (External)
Cache - temporary storage for instructions and data that the processor is likely to use frequently, thus speeding up processing
Level 1 (L1) internal cache - built into the microprocessor (8-256 kilobytes – operates fast)
Level 2 (L2) external cache - consists of RAM chips outside microprocessor (64-2MB)
Virtual memory - current operating systems allow for use of free hard-disk space used to extend the capacity of RAM
Processor searches for data or instructions in the following order: L1 L2
RAM
Virtual memory

20. Ports & Cables
Types of ports (connecting socket or jack on the outside of the system unit into which are plugged different kinds of cables):
Serial port - sends bits one at a time, one after another (keyboards, mouse, monitor, modem)
Parallel port
SCSI port
USB port
Dedicated port
Infrared port

21. Ports & Cables Serial port
Parallel port - transmits 8 bits simultaneously (fast data over short distances – 15 ft) (printers, external zip drive)
SCSI port
USB port
Dedicated port
Infrared port
Parallel port is third from left on bottom of display.
Parallel ports are faster than serial ports, but can transmit information efficiently only up to 15 feet.

22. Ports & Cables Serial port Parallel port
SCSI port - allows fast data to be transmitted in a “daisy chain” to up to 7 devices
USB port
Dedicated port
Infrared port
SCSI - Small Computer System Interface.

23. Ports & Cables Serial port Parallel port SCSI port
USB Port (universal serial bus) - can theoretically connect up to 127 peripheral devices daisy-chained to one general-purpose port (allows plug & play – so peripheral devices & expansions cards can be automatically configured while they are being installed.
Dedicated port
Infrared port
USB (Universal Serial Bus)
Plug and Play - allows peripheral devices and expansion cards to be automatically configured while they are being installed.

24. Ports & Cables Serial port Parallel port SCSI port USB
Dedicated port - special-purpose ports
Infrared port
Dedicated ports: mouse port, telephone jack, modem port, and keyboard port

25. Ports & Cables Serial port Parallel port SCSI port USB
Dedicated port - special-purpose ports
Infrared port - allows a computer to make a cableless connection with infrared-capable devices (handheld TV remote)

26. Expandability: Buses & Cards (Open vs. closed architecture)
Expansion slots- sockets on the motherboard into which you can plug expansion cards
Expansion cards - circuit boards that provide more memory or that control peripheral devices

27. Expandability: Buses & Cards
ISA bus (industry standard architecture) - for ordinary low-speed uses; the most widely used expansion bus
PCI bus (peripheral component interconnect)- for higher-speed uses; used to connect graphics cards, sound cards, modems, and high-speed network cards
AGP bus (accelerated graphics port) - for even higher speeds and 3D graphics
ISA (Industry Standard Architecture)
PCI (Peripheral Component Interconnect)
AGP (Accelerated Graphics Port)
Note: system bus connects CPU to itself and to main memory

28. Expandability: Buses & Cards
Graphics cards - for monitors
Sound cards - for speakers and audio output
Modem cards - for remote communication via phone lines
Network interface cards - for remote communication via cable
PC cards - for laptop computers (formally PCMCIA cards)
Graphic card - converts signals from the computer into video signals that can be displayed as images on a monitor.
Sound card - used to transmit digital sounds through speakers, microphones, and headsets.
Network interface card - allows the transmission of data over a cable network.
PC card - thin, credit-card size device used principally on laptop computers to expand capabilities.

29. 4.3 Secondary Storage Floppy disk
a removable flat piece of mylar plastic packaged in a 3.5-inch plastic case
Data & programs are stored on disks coating with magnetic spots following on/off patterns of data representation.
Write-protect notch - allows you to prevent a diskette from being written to.
Tracks - concentric circles on which data is recorded.
Sectors - invisible wedge-shaped sections used for storage reference purposes.
Read/write head - used to transfer data between the computer and the disk.
Tracks
sectors

30. DISK STORAGE Floppy disk – 1.44 MB (400 typewritten pages)
Zip disks or 250 Mb
*SuperDisks Mb
*HiFD disks Mb
*Drive can also read floppy
Zip disks manufactured by Iomega Corp.
SuperDisks manufactured by Imation.
HiFD disks manufactured by Sony.
SuperDisk drive and HiFD drive can also read 1.44 Mb diskettes, which the Zip disk drive cannot do.

31. Hard Disks
Hard disks - thin but rigid metal platters covered with a substance that allows data to be held in the form of magnetized spots
Read/write head does not touch disk; rides on air cushion

32. Hard Disks
Head crash - event that happens when the surface of the read/write head or particles on its surface come into contact with the surface of the hard-disk platter, causing the loss of some or all of the data on the disk

33. Hard Disks
Nonremovable hard disks - housed in a microcomputer system unit and used to store nearly all programs and most data files
Hard-disk controller - a special-purpose circuit board that positions the disk and read/write heads and manages the flow of data and instructions to and from the disk.
See p. 164

34. Bits on disk - dark stripes are 0 bits and bright stripes are 1 bits
Hard Disks
Removable hard disks - one or two platters enclosed along with read/write heads in a hard plastic case, which is inserted into a microcomputer’s cartridge drive
Bits on disk - dark stripes are 0 bits and bright stripes are 1 bits
Also called hard-disk cartridges.

35. Optical Disks: CDs & DVDs
Optical disk - a removable disk on which data is written and read through the use of laser beams

36. Optical Disks: CDs & DVDs
CD-ROM - read only. For pre-recorded text, graphics, and sound
CD-R - for recording on once
CD-RW - for rewriting many times
Discussion Question:
How does a DVD-ROM store so much information (up to 17 gigabytes) as compared to a CD-ROM (about 600 megabytes)?
Answer: Like a CD, the surface of a DVD contains microscopic pits, which represent the 0s and 1s of digital code that can be read by a laser. The pits on the DVD, however, are much smaller and grouped more closely together than those on a CD, allowing far more information to be represented. Also, the laser beam used focuses on pits roughly half the size of those on current audio CDs. In addition, the DVD format allows for two layers of data-defining pits, not just one. Finally, engineers have succeeded in squeezing more data into fewer pits, principally through data compression.
CD-Rom Drive’s speed denoted as data transfer by X which represents rate of 150 kilobytes per second. (44X = 44x150 kb)

37. Optical Disks: CDs & DVDs
DVD-ROM - for reading only [extremely high capacity ( gigabytes)
DVD-R - for recording on once
For rewriting many times:
DVD-RW
DVD-RAM
DVD+RW
FACTOID: Many people who have to travel often for work like to take along their laptop computers so that they can make good use of their time while flying in an airplane, waiting at airports, etc. The advent of DVD players in laptops made this an even more attractive alternative, as travelers could carry along a DVD movie for their own personal entertainment. More and more desktop and tower microcomputers are beginning to feature DVD players as well, which further blurs the distinction between a computer and a television. One company that has taken advantage of this increase in computer-based DVD players (accompanied by a similar increase in home-entertainment DVD players) is netflix.com This WWW-based business is an online substitute for a video rental store. Netflix members pay a fixed amount per month for as many movie DVDs as they can order, watch, and return (in prepaid mailing envelopes) to the company.

38. Magnetic Tape (up to 66 gigabytes)
Magnetic tape - thin plastic tape coated with a substance that can be magnetized (for 1s) or left non-magnetized (for 0s)
Tape cartridges - modules resembling audio cassettes that contain tape in rectangular, plastic housings

39. Smart Cards Smart card (holds up to 250 pgs of data)
Looks like a credit card but contains a microprocessor embedded in the card (e.g., telephone debit card)
Optical card (holds up to 2000 pgs of data) Plastic, laser-recordable, wallet-type card used with an optical-card reader
[Note: conventional credit card strip holds ½ page of data]
Discussion question:
Is your student ID card a smart card? If so, how have you used its capabilities?
Smart card in use

40. Flash Memory Cards Flash memory card –
circuitry on credit-card-size PC card that can be inserted into slots connecting to the motherboard
64 MB – projected up to 1 gigabyte
Memory Stick from Sony
Secure Digital (SD) card from Panasonic
Flash memory is nonvolatile - it retains data even when the power is turned off.

41. Concept Check
Which binary code is most often used with microcomputers?
ASCII (American Standard Code for Information Interchange)

42. Concept Check
How many bytes are in a terabyte?
One trillion

43. Concept Check
Which type of CD can be written to only once?
CD-R

44. Concept Check
Which binary code can represent all the characters of virtually every language in existence?
UNICODE

45. Concept Check
Which chip architecture provides faster processing speed--CISC or RISC?
RISC

46. Concept Check Which measure of storage represents one billion bytes?
Gigabyte

47. Concept Check What are the two parts of the CPU?
Control unit and arithmetic/logic unit (ALU)

48. Concept Check
What is the term for increasing a computer’s capabilities by adding hardware to perform tasks beyond the scope of the basic system?
Expansion

49. Concept Check What is a gigahertz?
A measure of processing speed representing one billion cycles per second

50. Concept Check
What is the term for the special high-speed memory area on a chip that the CPU can access quickly?
Cache

51. Concept Check
What element are wafers composed of?
Silicon

52. Concept Check What are the four steps of the machine cycle?
Fetch an instruction
Decode the instruction
Execute the instruction
Store the result