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McGraw-Hill
Hardware: The CPU & Storage
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McGraw-Hill
4.1 Microchips, Miniaturization, &
Mobility
4-3
 Vacuum Tubes
 Vacuum tubes were the original logic gates of computers; they
controlled the flow of electricity in circuits.
 They looked like light bulbs, were hot, and burned out quickly.
 A circuit is a closed path that can be flowed by electric current.
 Transistors Replaced Vacuum Tubes
 The original transistors, tiny electronic switches, were 1/100th
the size of vacuum tubes (less power used, faster, more
reliable)
 Transistors form part of an integrated circuit--all the parts of an
electronic circuit embedded on a single silicon chip.
 One integrated circuit contains more than a million transistors.
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4.1 Microchips, Miniaturization, &
Mobility
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 Silicon & Semiconductors


Silicon: A semiconductor made of clay and sand
Semiconductor: A material whose electrical properties
are intermediate between a good conductor and a
nonconductor of electricity



Perfect underlayer for highly conductive, complex circuits
Microchips (Microprocessors) are made from
semiconductors
Chip: A tiny piece of silicon that contains millions of
microminiature integrated electronic circuits
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4.1 Microchips, Miniaturization, &
Mobility
4-5
 Miniaturization Miracles

Microchips


Microprocessors



Store and process data in electronic devices
The miniaturized circuitry of an entire computer processor
(“brain”) on a single chip
Contains the central processing unit (CPU), which
processes data into information
The development of microchips and processors has
enabled the development of small, mobile electronic
devices.
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4.2 The System Unit: The Basics
 Binary System: the basic data-representation method for
computers uses just two numbers: 0 and 1, representing the off/on
states of electricity or light pulses.
 All data and program instructions in the computer are
represented as binary
 Bit: each 0 or 1 is a bit
 Byte: a group of 8 bits = 1 character, digit, or other value
 Kilobyte: 1,000 (1,024) bytes
 Megabyte: 1 Million (1,048,576) bytes
 Gigabyte: 1 Billion (1,073,741,824) bytes
 Terabyte: 1 Trillion (1,009,511,627,576) bytes
 Petabyte: 1 quadrillion bytes
 Exabyte: 1 quintillion bytes
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4.2 The System Unit: The Basics
 Binary coding schemes assign a unique binary code to
each character.



EBCDIC
 Requires 8 bits per character
 Used for IBM mainframes
ASCII
 Requires 7 or 8 bits per character, depending on the version
 8 bit Extended ASCII provides 256 characters
 Commonly used for microcomputers
Unicode
 Requires 16 bits per character
 Handles 65,536 characters—used for Chinese and
Japanese
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4.2 The System Unit: The Basics
 Machine Language


A binary-type programming language (0s and 1s) built
into the CPU that is run directly by the computer
Each CPU type has its own machine language
 Language Translators

The computer’s system software converts higher-level
language instructions and data into machine language so
that the processor can “understand” what to do.
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4.2 The System Unit: The Basics
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4.2 The System Unit: The Basics
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4.2 The System Unit: The Basics
Computer Terms
 Names
Bay
Power Supply
Surge Protector
Voltage Regulator
UPS
Motherboard
Microprocessor
Chipset

Definitions
Opening in the computer cabinet used for the installation of
electrical equipment.
This converts AC to DC to run the computer.
Protects the computer from being damaged by power spikes.
Plug your computer into one.
Protects a computer against brownouts or low power conditions
that happen a lot in summer.
Uninterruptible Power Supply. Battery-operated device that
provides power for a limited time when there is a blackout.
The main system board of the computer (also systemboard).
The miniaturized circuitry of a computer processor.
Groups of interconnected chips on the motherboard that control
information flow between the microprocessor and other
system components connected to the motherboard.
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4.2 The System Unit: The Basics
 Two main types of microprocessors are made for
microcomputers--one for PCs and one for Macs.
 Microprocessor manufacturers are Intel, AMD,
Motorola/Freescale, and IBM.
 Multicore processors have more than one processor
“core” on a silicon chip, which allows computers to ru
faster.
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4.2 The System Unit: The Basics
 Processing Speeds


Every microprocessor has a system clock built in that
controls the chip’s processing speed.
Older CPU processing speeds are in megahertz


Current CPU processing speeds are in gigahertz


1 MHz = 1 million cycles per second
1 GHz = 1 billion cycles per second
The faster a CPU runs, the more power it consumes, and
the more heat it generates
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4.2 The System Unit: The Basics
 Processing Speeds (continued)

Workstation and mainframe speeds are measured in
MIPS




MIPS stands for millions of instructions per second
Workstations perform at 100 MIPS or more
Mainframes now perform as fast as 981,024 MIPS
Supercomputer processing speed is measured in
flops


Flops stands for floating-point operations per second
Los Alamos Lab’s new Roadrunner has a speed of 1,105
teraflops, or 1,000 trillion operations per second.
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4.3 More on the System Unit
Parts of the CPU
Name
Definition
Word size
The number of bits the processor can process at
any one time
CPU
The central processing unit (chip) has two parts;
the control unit and the ALU
Control unit
The part of the CPU that deciphers instructions
and carries them out
Arithmetic Logic
Unit (ALU)
The part of the CPU that performs mathematical
and logical operations
Registers
High-speed storage areas that temporarily store
data during processing
Buses
Electrical data roadways used to transmit bits
within the CPU and between CPU and other
motherboard components
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4.3 More on the System Unit
 Memory

Two type of storage: primary and secondary


Primary storage = “memory,” “main memory,” “RAM”; this
type of memory is temporary and volatile
Secondary storage = “storage” disks and tape; this type of
memory is relatively permanent and nonvolatile
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4.3 More on the System Unit
How Memory Works
Primary Memory Chips
RAM
ROM
CMOS
Flash
Explanation
Random Access Memory chips are volatile and hold:
a.
Software instructions
b.
Data before & after the CPU processes it
Read Only Memory
a.
Cannot be written on or erased without special
equipment
b.
Are loaded at factory with fixed (permanent) startup instructions (BIOS), that tell the computer how
to load the operating system
Complementary Metal Oxide Semiconductor
a.
Powered by a battery
b.
Contains time, date, calendar, boot password
Nonvolatile memory that can be erased and
reprogrammed more than once
a.
Doesn’t require a battery
b.
Used in newer PCs for BIOS instructions
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4.3 More on the System Unit
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Types of RAM
RAM Chip Types
DRAM
1.
SDRAM
2.
Synchronous Dynamic RAM is synchronized by the
system clock and is much faster than DRAM
SRAM
3.
Static RAM is faster than DRAM and retains its
contents without having to be refreshed by CPU
DDR-SDRAM
4.
SIMM
5.
DIMM
6.
Double-data rate synchronous dynamic RAM; type
used most commonly in microcomputers
Single Inline Memory Module has RAM chips on
only one side; insert in expansion slot to increase
RAM
Dual Inline Memory Module has chips on both
sides; insert in expansion slot to increase RAM
Explanation
Dynamic RAM must be constantly refreshed by the
CPU or it loses its contents
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4.3 More on the System Unit
 Speeding up Processing: Cache


The CPU works much faster than RAM, so it often must
wait for information
Cache temporarily stores instructions and data that the
processor uses frequently to speed up processing



Level 1 cache is part of the microprocessor
 Holds 8 to 256 kb
 Faster than Level 2 cache
Level 2 cache is external cache
 Holds 64 kb to 2 Mb
Level 3 cache is on the motherboard
 Comes on very high-end computers
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4.3 More on the System Unit
 Virtual Memory—also used to speed up processing



This type of memory is unused hard disk or optical (CD)
space that the processor uses to extend the capacity of
RAM
The processor goes first to L1 cache, then L2 cache,
then RAM, then virtual memory
Each type of memory is slower than its predecessor
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4.3 More on the System Unit
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Speeding up Processing
 Additional Methods of Speeding up Processing
 Interleaving
 Bursting
 Pipelining
 Superscalar Architecture and Hyperthreading
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4.3 More on the System Unit
 A port is a connecting socket or jack on the
outside of the computer unit into which are
plugged different kinds of cables
 Ports are used to connect peripheral devices
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4.3 More on the System Unit
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Ports
Port Type
Description
Serial Port
Used to transmit data slowly over long distances
a.
Sends data sequentially, one bit at a time
b.
Used to connect keyboard, mouse, monitors,
dial-up modems
For transmitting data quickly over short distances
a.
Transmits 8 bytes simultaneously
b.
Connects printers, external disks, tape
backups
Small Computer System Interface
a.
Connects up to 7 devices in a daisy chain
b.
Transmits data 32 bits at a time
Universal Serial Bus can theoretically connect up
to 127 peripheral devices in a daisy chain
Parallel Port
SCSI Port
USB Port
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4.3 More on the System Unit
 USB

Goals



Be low-cost
Be able to connect lots of devices
Be hot swappable



People hate rebooting after connecting new devices, because it
takes time
Hot swapping means a device can be connected/disconnected
without rebooting
Permit plug and play

Devices are automatically configured when they are installed –
no need to download new drivers
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4.3 More on the System Unit
 USB (continued)

Standards





USB 1.1--the original standard
USB 2.0--the current standard for new PCs
USB 3.0–for high-end computers
USB OTG (On the GO) is used for small peripherals, such as
cellphones
Connectors




A--in USB Type 1.1 and 2.0
B--in USB Type 1.1 and 2.0
Mini B–in USB Type 2.0
Mini A–in USB OTG
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4.3 More on the System Unit
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Specialized Expansion Ports
Port Type
Description
FireWire
Intended for devices working with lots of data; used
for camcorders, DVD players, TVs
MIDI
Musical Instrument Digital Interface
a.
b.
IrDA
Bluetooth
Connects musical instruments
Used in creating, recording, editing, performing music
Infrared Data Association: Infrared ports used to
make a cableless connection
Uses short-range radio waves that transmit up to 30
ft; connects computers to printers, keyboards, headsets,
and other devices
Ethernet
Multimedia
The standard for linking all devices in a Local Area
Network
For special multimedia devices, such as gaming
consoles, TVs, VCRs, speakers,digital projectors,
etc.
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4.3 More on the System Unit
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Expansion Cards
 If a computer uses closed architecture, no expansion
cards can be added; if the computer uses open
architecture, expansion cards can be inserted in
expansion slots inside the computer, connected to the
motherboard.
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4.3 More on the System Unit
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Expansion Buses
Expansion cards connect with different
types of buses on the motherboard.
Bus
PCI bus
AGP bus
PCIe Express bus
Description
Peripheral Component Interconnect
a. For high-speed connections
b. 32 or 64 bits wide
c. Typically used for sound cards, modems,
high-speed network cards
Accelerated Graphics Port
a. Twice the speed of PCI bus
b. Supports video and 3-D graphics cards
Can outperform AGP and is more reliable
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4.3 More on the System Unit
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Examples of Some Expansion Cards
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4.3 More on the System Unit
 Types of Expansion Cards

Graphics cards (for monitors)



Sound cards (for speakers and audio output)


Also called a video card, video RAM (VRAM), or video
adapter
Converts signals from computer into video signals that can
be displayed as images on a monitor
Used to convert and transmit digital sounds through analog
speakers, microphones, and headsets
Modem cards (for remote communication via phone
lines)
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4.3 More on the System Unit
 Types of Expansion Cards (continued)

Network interface cards (for remote communication via
cable)


Allows the transmission of data over a cable network
PC cards (for laptop computers)

Thin, credit card-size flash memory devices used principally
on laptop computers to expand capabilities
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4-32
4.4 Secondary Storage
Storage Types
Descriptions
Floppy disks
Removable disks; Floppies store 1.44 MB; mostly obsolete,
except on legacy systems
Hard disks
Made from thin rigid metal covered with magnetizable substrate.
Most disks have 2 or more platters
Optical disks
Removable CDs and DVDs
Magnetic tape
Thin plastic tape coated with magnetizable substance
Smart Cards
Like a credit card, but contains a microprocessor and memory
chips
Flash memory
Nonvolatile memory – no moving parts
Online secondary storage
Lets you store data on an online vendor’s server
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4.4 Secondary Storage
 Floppy Disks






Flat piece of mylar plastic inside a 3.5” plastic case
Store about 1.44 MB
Data is recorded in tracks: concentric recording bands
Formatting breaks the tracks into small wedge-shaped
sectors
Read/Write head transfers data between the computer
and disk
Not used much any more, except on some legacy
systems
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4.4 Secondary Storage
 Hard Disks

Thin, rigid metal, glass, or ceramic platters covered with
a substance that allows data to be held in the form of
magnetized spots





The more platters there are, the higher the drive capacity
Store data in tracks, sectors, and clusters
Formatting creates a file allocation table that maps files to
clusters or inodes
Drive heads ride on .000001” cushion of air, and can crash!
Important data should always be backed up!
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4-35
4.4 Secondary Storage
 Hard Disks (continued)

Hard Disk Types:



External Hard Disk – a freestanding disk drive
Removable Hard Disk – inserted into a bay or a cartridge
drive built into the computer’s system unit
Hard Disk Controllers – special circuit boards that control
the read/write heads and manage the flow of data to and
from the hard disk



EIDE – Enhanced Integrated Drive Electronics (e.g., SATA)
SCSI – Faster than EIDE controllers
Fibre Channel – Used in large servers – faster and costlier
than SCSI
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4.4 Secondary Storage
 Optical Disks


CDs (compact disks) and DVDs (digital versatile/video
disks) are optical disks
Data is written and read using lasers, not a disk
read/write head



CD-ROM is Compact Disk Read-Only Memory
CD-R (compact disk-recordable) is used for recording only
once
CD-RW (compact disk-rewritable)is an erasable optical disk
that can both record and erase data over and over again
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4.4 Secondary Storage
 Optical Disks (continued)




DVD is a CD-style disk with extremely high capacity
DVD-R (DVD-recordable) is used for recording only once
DVD-RW, DVD-RAM, DVD+RW are reusable DVDs
Blu-ray is an optical-disk format used to record, rewrite,
and play back high-definition (HD) video, as well as to
store large amounts of data.
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4.4 Secondary Storage
 Magnetic Tape

Thin plastic tape coated with a substance that can be
magnetized



Store terabytes of data
Used in the form of tape cartridges
Still popular for large backups because of their large data
capacity
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4.4 Secondary Storage
 Smart Cards

Resembles a credit card, but contains a microprocessor
and memory chips



May function on three levels: credit, debit, and/or personal
information
Storage capacity: around 10 MBs
Contact smart cards



Must be swiped through card readers
Can wear out from use
Contactless smart cards

Read when held in front of a low-powered laser
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4.4 Secondary Storage
 Flash Memory

Nonvolatile memory with no moving parts

Available as:




Flash memory cards
 Insert these into a flash port of a camera, handheld PC,
smartphone
Flash memory sticks
 A form of flash memory that plugs into a memory stick port in, for
example, a digital camera, camcorder, photo printer
Flash memory drives (keychain drives)
 A finger-sized module of flash memory
 Plugs into the USB port of most PCs and Macintoshes
Solid-state memory drives
 Have greater capacity than flash memory drives but are expensive
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4.4 Secondary Storage
 Online Secondary Storage (Cloud Storage)

Allows you to use the internet to back up your data

Sign up with a vendor and receive access to software that
allows you to upload your data to that company’s server
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4-42
4.5 Future Developments in
Processing & Storage
New Technology
Description of Processing Technology
Application
Virtualization
Doing processing online instead of buying one’s
own software and some hardware.
Nanotechnology
Tiny machines work at a molecular level to make
nanocircuits
Optical Computing
Uses lasers and light, not electricity
DNA Computing
Uses strands of synthetic DNA to store data
Quantum Computing
Based on quantum mechanics and stores
information using particle states
Better Batteries
Wireless charging of batteries, longer-lasting
batteries
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4.5 Future Developments in
Processing & Storage
 Future Developments in Secondary Storage

Higher-density disks



Perpendicular recording technology: stacking magnetic bits
vertically on the surface of a platter (instead of horizontally,
as usual)
Molecular electronics– storage at the subatomic level
Holograms, molecular magnets, bacteria
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