LongTerm Memory, Disk Drives, Optical Storage

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Long-Term Memory, Disk Drives, Optical Storage

• Dr. Harold D. Camp
• IT 212 002
• 22 March 2007

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Question 1

• (10 Points) Define the terms
• Computer
• An electronic device that stores, retrieves, and
  processes data, and can be programmed with
  instructions. A computer is composed of hardware
  and software, and can exist in a variety of sizes
  and configurations.
• Mainframe
• A large, stationary computer that requires space
  in an air conditioned room.
• Such machines store massive amounts of data,
  support many users, and run a wide variety of
  applications simultaneously
• Before home computers became available in the
  early 1980s, mainframes were the only computers.
• They were used by governments world-wide and
  large corporations.
• IBM and Unisys are the leading manufacturers of
  mainframe computers.
• Personal Computer
• Any combination of processor, input device and
  output device designed for use by a single
  individual.
• Personal computers may also be called
  workstations.
• Personal computers may have a character
  orientation, a graphical orientation, may be
  connected to other personal computers, or may
  operate in a stand alone mode, and may or may not
  have connectivity to a mainframe.

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Question 2

• (10 Points) The four basic functions of a
  computer are input, processing, output, and
  memory, give a diagram of how these functions
  interact.

Storage
Input
Processor
Output
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Question 3

• (10 Points) Describe the evolution of the basic
  components of computers, including a
  characterization of 1st, 2nd, and 3rd generation
  computer components.
• First Generation
• Vacuum tube-based computers were in use
  throughout the 1950s,
• Second Generation
• Replaced in the 1960s by transistor-based
  devices,
• Smaller, faster, cheaper, less power and more
  reliable.
• Third Generation
• By the 1970s, integrated circuit technology
• Creation of microprocessors such as the Intel
  4004
• Leap in size, speed, cost and reliability.

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Question 4

• (10 Points) Describe the five steps to install a
  Plug and Play device. Give examples of three
  Plug and Play devices.
• When a hardware device is connected as when you
  plug a USB camera into a USB port Plug and Play
  Manager goes through the following steps to
  install the device.
• After receiving an insertion interrupt, Plug and
  Play Manager checks what hardware resources the
  device needs
• memory ranges, I/O ranges, and DMA channels. Plug
  and Play Manager then assigns those resources.
• Plug and Play Manager checks the hardware
  identification number of the device.
• Plug and Play Manager then checks the hard drive,
  floppy drives, CD-ROM drives, and Windows Update
  for drivers that match the number of the device.
• If multiple drivers are found, Plug and Play
  Manager chooses the driver that is the best match
  by looking for the closest hardware ID or
  compatible ID match, driver signatures, and other
  driver features.
• Plug and Play Manager then installs the
  best-match driver and the operating system starts
  the device.
• Examples Digital Camera, Thumb Drive, Graphics
  Card

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Question 5

• (10 Points) Give an example of a device that
  would plug into the
• System (or Front Side) bus.
• CPU, Bus Bridge, or RAM
• The PCI bus.
• Digital Camera
• The IDE bus.
• Disk Drive

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Question 6

• (10 Points) Describe the functions of the Front
  Side Bus and the Back Side Bus.
• System or local bus
• Connects the microprocessor (CPU) and the system
  memory
• Fastest bus in the system
• The backside bus
• A separate connection between the processor and
  the Level 2 cache
• Operates faster than frontside bus
• Same speed as the processor
• Caching works efficiently as possible.

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Question 7

• (10 Points) In base 2, how many bits are required
  to address a 1 MByte memory and how many Bytes
  are in a Segment in a PCs memory?
• 1 MByte 220 MByte
• Therefore, 20 bits address 1 MByte
• PC computer memory is divided into segments,
• 64 kilobytes each (65,536 bytes, to be exact)
• Segment register in microprocessor indicates
  segment is to be accessed

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Question 8

• (10 Points) Windows peripheral devices are memory
  mapped. Describe how the Memory Management,
  Device Drivers, and I/O Management Layers work
  together.
• Managing all the resources of the computer system
  is a large part of the operating system's
  function, providing a relatively simple,
  consistent way for applications and humans to use
  the power of the hardware is a crucial part of
  their reason for existing.
• When an operating system manages the computer's
  memory, there are two broad tasks to be
  accomplished
• Each process must have enough memory in which to
  execute.
• Manage the different types of memory in the
  system so that each process can run most
  effectively.
• Device Drivers take data the operating system has
  defined as a file and translate them into streams
  of bits that the device can use.
• Managing input and output is a matter of managing
  storage facilities that take or send a stream of
  bits from or to a device at a rate the CPU to
  cope with.
• These three layers work together to allow an
  application program to receive the machines
  resources necessary to perform its desired
  functions

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Question 9

• (10 Points) How does the application programmer
  take advantage of the Layered Windows
  Architecture? (Hint machine independence)
• Application Program Interfaces (APIs) let
  application programmers use functions of the
  computer and operating system without having to
  directly keep track of all the details in the
  CPU's operation.
• Because the programmer has written a program to
  use the API for disk storage, the programmer
  doesn't have to keep up with the instruction
  codes, data types and response codes for every
  possible hard disk and tape drive.
• The operating system, connects the application to
  drivers for the various hardware subsystems,
  deals with the changing details of the hardware
• The programmer must simply write code for the API
  and trust the operating system to do the rest.
• Therefore, in theory, the program works the same
  on all Windows computers, regardless of
  manufacturer or configuration

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Question 10

• (10 Points) Describe the basic relationship of
  the Basic Input/Output System (BIOS) to the
  Layered Windows Architecture.
• BIOS, in computing, stands for Basic Input/Output
  System also incorrectly known as Basic Integrated
  Operating System. BIOS refers to the firmware
  code run by a computer when first powered on. The
  primary function of the BIOS is to prepare the
  machine so other software programs that use the
  Layered Windows Architecture can load, execute,
  and assume control of the computer. This process
  is known as booting up.

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Back to Learning

• Chapter 9
• Long Term Memory, Disk Drives, Optical Storage
  and Optical Storage

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Volatile or Non-Volatile

• Volatile memory does not retain its information
  without constand power
• Needs refresh
• Non-Volatile maintains information indefinitely

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Long-Term Storage Old New
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History
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History
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History
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(No Transcript)
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How Magnetic Storage Works

• Media used in removable magnetic-storage devices
  is coated with iron oxide
• A ferromagnetic material
• If you expose it to a magnetic field it is
  permanently magnetized
• The media is typically called a disk or a
  cartridge
• The drive uses a motor to rotate the media at a
  high speed
• Accesses (reads) the stored information using
  small devices called heads
• Each head has a tiny electromagnet (an iron core
  wrapped with wire)
• The electromagnet applies a magnetic flux to the
  oxide on the media
• The oxide permanently "remembers" the flux last
  saw
• During writing, data signal sent through a coil
  to create a magnetic field
• At the gap, the magnetic flux forms a fringe
  pattern
• The flux magnetizes the oxide on the media
• During reading, the read head pulls a varying
  magnetic field across the gap
• Creates a varying magnetic field in the core and
  a signal in the coil

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How Optical Storage Works
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How Optical Storage Works

• Media used in removable magnetic-storage devices
  is coated with iron oxide
• A ferromagnetic material
• If you expose it to a magnetic field it is
  permanently magnetized
• The media is typically called a disk or a
  cartridge
• The drive uses a motor to rotate the media at a
  high speed
• Accesses (reads) the stored information using
  small devices called heads
• Each head has a tiny electromagnet (an iron core
  wrapped with wire)
• The electromagnet applies a magnetic flux to the
  oxide on the media
• The oxide permanently "remembers" the flux last
  saw
• During writing, data signal sent through a coil
  to create a magnetic field
• At the gap, the magnetic flux forms a fringe
  pattern
• The flux magnetizes the oxide on the media
• During reading, the read head pulls a varying
  magnetic field across the gap
• Creates a varying magnetic field in the core and
  a signal in the coil

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Key Concepts

• Access Time
• Latency
• Buffer
• Cyclic Redundancy Check
• Direct Memory Access
• Data Transfer Rate
• Cluster
• File Allocation Table
• Format
• Fragmentation
• Gigabytr
• Read, Read-Only, Write, Rewritable
• Sector and Track
• Seek Time
• Sequential vs. Random Access
• Settle Time

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Software and Flows
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Key Points

• Interpreters vs. Compilers
• Program, Kernel, Subprograms, Routines, Calls
• Lexical Analysis and Parsing
• Flow Charts
• American National Standards Institute (ANSI)

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Homework 6

• For an application that balances your checkbook,
  build three flow charts
• Kernel flow chart showing the process of
  balancing a check book
• Routine flow chart showing the accessing of data
  from a hard drive (that is called from the
  Kernel)
• Parsing flow chart showing how to input a number
  (in ASCII) and determine its value in machine
  readable format