1. Computer Performance & Storage Devices
Computer Technology
Part 3
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ERMS 12/13 Part 3

2. Computer Performance
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ERMS 12/13 Part 3

3. Boot Process
Sequence of events that occurs between the time you turn on a computer and the time that it becomes ready to accept commands.
Purposes
Runs a diagnostic test to make sure everything is working.
Loading the operating system, so the computer can carry out basic operations.
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ERMS 12/13 Part 3

4. 6 events of the boot process:
Power up
Start boot program
Power-on self-test
Identify peripheral devices
Load operation system
Check configuration and customization
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5. Circuits
The path from one component of a computer to another that data uses to travel.
Circuits run between
RAM and the microprocessor
RAM and various storage devices
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ERMS 12/13 Part 3

6. Silicon Chip Silicon is melted sand.
What the circuits are embedded into to keep them together.
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7. Megahertz (mHz)
A measurement used to describe the speed of the system clock.
A megahertz is equal to one million cycles (or pulses) per second.
1.3 GHz means that the microprocessor’s clock operates at a speed of 1.3 BILLION cycles per second.
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ERMS 12/13 Part 3

8. RAM vs. ROM
System Crash!
ROM
RAM
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9. RAM vs. ROM RAM RAM Read Only Memory Random Access Memory
Temporary—content is lost if the device is powered off
Runs all currently open programs – the more open programs the slower your computer is
RAM is rather inexpensive—getting more RAM can speed up your computer. But there is a limit to how much RAM your computer can have.
Read Only Memory
Permanent Storage
Where all your programs and files are saved—your hard drive.
The bigger your hard drive, the more you can save there.
Hard drives rarely crash—anything saved there is pretty safe—but it’s always good to have backups!
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ERMS 12/13 Part 3

10. Binary Number System
A method for representing letters or numbers using only two digits, 0 and 1.
Bit
Each 0 or 1
Byte
8 bits
Also referred to as Base 2 Binary Code.
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ERMS 12/13 Part 3

11. Byte Kilobyte Megabyte Gigabyte Terabyte Memory Measurements Bit
Each 0 or 1
Byte
8 bits
Kilobyte
Approximately 1,000 bytes
Exactly 1,024 bytes
Megabyte
Approximately 1 million bytes
Exactly 1,048,576 bytes
Gigabyte
Approximately 1 billion bytes
Terabyte
Approximately 1 trillion bytes
Petabyte, Exabyte, Zettabyte, Zottabyte, Brontobyte
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ERMS 12/13 Part 3

12. Storage Devices
Used to keep data when the power to the computer is turned off.
Medium/media
Location where data is stored.
Write-Protected - A disk that will not allow a user to make changes to files
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ERMS 12/13 Part 3

13. Hard Disk Usually mounted inside the computer’s system unit.
Can store billions of characters of data.
Stated in forms of bytes:
Megabytes or Gigabytes
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14. USB Flash Drive Also known as a “Jump Drive.”
Typically removable and rewritable, physically smaller than a floppy.
Storage capacities can be as large as 256 GB. Most are 2 to 8 GB.
Smaller, faster, thousands more times capacity, and are more durable and reliable.
Plug right into a USB port.
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ERMS 12/13 Part 3

15. Memory Card
Used for storing digital information, usually for digital camera, mobile phones, laptops, MP3 Players, and video game consoles.
Small, re-recordable and can retain data without power.
Usually store from 2 to 8 GB.
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16. Optical Storage
Means of recording data as light and dark spots on CD or DVD.
Reading is done through a low-power laser light.
Pits
Dark spots
Lands
Lighter, non-spotted surface areas
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17. CD-ROM “CD – Read Only Memory” Also called CD-R
Storage device that uses laser technology to read data that is permanently stored on compact disks, cannot be used to write data to a disk.
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18. CD-RW
“CD-Read Write”
A storage device that reads data from CD’s and also can write data to CD’s.
Similar to a CD-ROM, but has the ability to write to CD.
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19. DVD-ROM “Digital Video Disks – Read Only Memory”
Reads data from CD’s (audio and data) and DVD’s (data or movie)
Cannot be used to write data to a disk.
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ERMS 12/13 Part 3