Chapter 2 - CS3 - Hardware Flashcards
What are the 5 basic components of PC hardware?
CPU, memory, circuit board, storage, and input/output
Moore’s law
Number of transistors on a chip will double every two years > computing power will double for same price point
What is the CPU?
Central Processing Unit, the “brain”
Interprets & carries out commands
What are the two units of the CPU?
Arithmetic Logic Unit = actual processing by performing math & logic operations
Control Unit = coordinates & controls all other parts of the computer system
How do you measure the speed of a CPU?
“Clock time” of CPU is measured in hertz = one cycle per second
Bus
The electrical connection b/w different computer components; highway of parallel wires
Motherboard
Main circuit board - houses all essential chips and CPU, memory, storage all connect into the motherboard
RAM
Random Access Memory = “working memory”
Temporarily holds data & instructions
Bit
Binary digit, 0 or 1
Byte
8 bits; a byte is a single character (like the letter “T”)
1 megabyte = 1m bytes = 200 pgs of text or one screen-size image
Binary numbering system
Base 2, digits 0 and 1
Hexadecimal numbering system
Base 16: 0-9, A-F
Octal numbering system
Base 8: 0-6
Decimal numbering system
Base 10: 0-9
Hertz
One cycle per second
e.g., kilohertz = 1000 cycles per second
Hard disk
Long-term data storage
SSD
Solid-state drive - long-term data storage
Oversized/ sophisticated flash memory stick
SSD vs. Hard disk
SSD is more expensive, lighter & faster b/c it uses flash memory (instead of disks), quieter, more durable, less power consumption, longer life
Machine cycle
- Control unit fetches instructions & data from memory
- Control unit decodes instructions & sends to ALU
- ALU performs calculations
- Results of calculation is stored in memory
Volatile memory
Loses its contents when computer is turned off
Ex: RAM
Nonvolatile memory
Does not lose contents when computer is off
Ex: ROM, flash memory
ROM
Contents permanently burned in the chip
Input devices
Devices that feed data INTO the computer - keyboard, mouse, scanner
Output devices
Devices that show output - projector, monitor, printer
Surge protector (suppressor)
Uses electrical components to provide a stable current flow and minimize the chances of an over-voltage
Storage medium
Physical material on which computer keeps data, programs, applications
Storage device
Records & retrieves data from the storage media
Reading
Transferring data from storage media to memory
Writing
Transferring data from memory to storage media
Hard disk vs. hard drive
Hard disk is storage medium - the disk you store data on
Hard drive is storage DEVICE - reads & writes data
The CPU can be thought of as the ___ of the computer.
Brain
List the following in increasing order (slowest to fastest): megahertz, kilohertz, gigahertz
kilohertz, megahertz, gigahertz
What was the first commercially successful portable PC? How heavy was it?
1983 - Compaq computer corp - 28 pounds
Why are PCs a commodity?
Very little differentiation between computers
Primary factor that controls their sale = PRICE!
