pc hardware grade 9. pc hardware outline what is a computer? what are examples of computers? what...
TRANSCRIPT
PC Hardware
Grade 9
PC Hardware Outline
• What is a computer?• What are examples of computers?• What types of PCs exist?• What is the typical PC hardware?• How might we evaluate a PC?
– In terms of Speed…– In terms of Storage Capacity…– In terms of Memory…
Four Primary Functions of a Computer
• Input
• Process
• Output
• Store
Types of Computers
• Supercomputer
• Server
• Embedded Computer
• Personal Computer
Supercomputer
Server
Embedded Computers
Personal Computers (PCs)
Types of PCs
• Desktop
• Laptop
• PDA
• Tablet PC
Computer Hardware
• Computer hardware can be classified in relation to the four primary functions of a computer (discussed earlier):
– Input devices– Output devices– Processing devices– Storage devices
Sample Classification
How are humans like a computer?
• Input devices?• Output devices?• Processing devices?• Storage devices?
How are humans like a computer?
• Input devices?– Hands, Ears, Eyes, Nose, (Our senses)
• Output devices?– Mouth, Hands, (Talking, writing, typing, etc)
• Processing?– Brain
• Storage?– Short term memory– Long term storage
The human computer
Output Output
Input
Long Term Storage! Short Term Memory!
Processing Information
Typical Desktop PC Hardware
• Central Processing Unit (CPU)• Motherboard• Random Access Memory (RAM) modules• Hard Drive• Keyboard• Mouse• Monitor• Power supply, case, etc.
Typical Desktop PC Hardware
Computer Part• CPU• Motherboard• RAM modules• Hard Drive• Keyboard• Mouse• Monitor• Power supply, case, etc.
Category• Processing device• Processing device• Storage/Processing device• Storage device• Input device• Input device• Output device• N/A
Consider editing a document on a PC
• When you type a letter on the keyboard, it is sent to the CPU as input.
• Your input travels through the motherboard and is stored in RAM. The RAM is short-term memory that holds programs and data you are using.
• The CPU processes your input as a document character and updates the output on the monitor to show the new character that you typed.
• Finally, when you save the document the information is stored for the long term on the hard disk drive.
A closer look at a motherboard…
Ports
Motherboard
Evaluating a computer
• SpeedSpeed– How fast can my PC process information?
• Memory CapacityMemory Capacity– How many programs can my PC use at once?
• Storage CapacityStorage Capacity– How many files can my PC save?
• Other components:Other components:– Can I watch DVDs? Can I play video games? Can I
connect my MP3 player?
Evaluating a computer
• SpeedSpeed– CPU speed
• Memory CapacityMemory Capacity– RAM size
• Storage CapacityStorage Capacity– Hard Drive size
• Other components:Other components:– Ex: Floppy drive, CD-ROM, DVD-RAM, video card,
USB ports
CPU speed• Measured in Hz (Cycles per second)
• CPU processes data during each cycle
• Early PCs ran at speeds such as 2MHz or 2,000,000 cycles per second:– 1 Hz = 1 cycle per second– 1 MHz = 1,000,000 Hz– 1 GHz = 1,000 MHz or 1,000,000,000 Hz
• Modern PC CPUs are typically between 1GHz and 3GHz
CPU speed
CPU
InputO
utput
Each cycle this process repeats!
The CPU The CPU cycle:cycle:
Before we talk about memory:
• ROM vs RAMROM vs RAM– ROM = Read Only Memory
• Can only read contents, can’t write them– RAM = Random Access Memory
• Can read or write to memory
• Volatile vs NonvolatileVolatile vs Nonvolatile– Volatile = Memory is lost if power goes out– Nonvolatile = Memory is more permanent
How much is a byte?
Name Abbr. Num. Bytes Relative SizeByte B 1 byte 1 character
Kilobyte KB 1,024 bytes ¼ typed pageMegabyte MB 1,048,576 bytes 768 pagesGigabyte GB 1,073,741,824B 786,432 pages
Storage Capacity
• In these slides I’m referring to the Long Term storage of a computer.
• This is the memory used to store files and programs for future use.
• In PCs, the internal hard drive is typically used for long term storage.
• More Hard Drive space = More files you can store
Storage Capacity
Medium Capabilities Capacity
Hard Drive RAM External: up to 2TBInternal: up to 500GB
CD / CD-RW ROM / RAM 700MB
DVD/DVD+RW ROM / RAM 4.7GB to 9.4GB
Flash Cards RAM 16MB to 8GB
Floppy Disk RAM 1.44MB
Flash Drive RAM Up to 6GB
Memory Capacity• In these slides I’m referring to the Short Term
storage of a computer.
• This is the memory used to hold programs and data while your computer is running.
• In PCs, the RAM is typically used for short term storage.
• More RAM space = More programs you can run at once.