Hardware CSCI 101
References Slides are heavily based on, and contain content from: Technology in Action Eleventh Edition by Evans, Martin, and Poatsy
Computer Functions Input Process Store Output
Computer Functions Input: Gathers data often from user entry Process: Takes data preforms instructions on it, to change it into the desired information Output: Displays data in a human readable form Storage: Saves data for use later
Bits and Bytes Information is stored in the computer as binary numbers (0 s and 1 s). Even images are stored in this way, where a combination of 0 s and 1 s represent each color in the picture
Measurement Units Since we can have large pieces of data we need ways to represent large binary numbers Unit Bit (0 or 1) Byte Kilobyte (KB) Megabyte (MB) Gigabyte (GB) Terabytes (TB) Petabyte (PB) Size 8 bits 2 10 bytes = 1024 bytes 2 20 bytes = about 1 million bytes 230 bytes = about 1 billion bytes 240 bytes = about 1 trillion bytes 250 bytes = about quadrillion bytes
Computer Hardware Hardware refers to the physical parts of the computer that can be touched. Examples: mouse keyboard graphics card hard disk drive
Input Devices Devices which let you enter data into the computer keyboard mouse / touchpad microphone scanner game controller stylus
Output Devices Sends data out from the computer to be seen in a human readable way: text, pictures, sound, Examples: Monitor Printer GPS Speakers
Key Components Inside the Computer Motherboard: Holds the CPU, Memory, system Bus, Bus: Shared communication channel for the components CPU: Computers Brain RAM: Holds data and instructions for currently running processes Input/Output Processors: Perform input/output related processing
Motherboard Main circuit board that contains the central electronic components of the computer Holds the CPU, memory, connectors for the hard drive, optical drive, video cards, Connects directly or indirectly to every part of the computer
Motherboard
Motherboard
System Bus Communication link that connects all the different parts of the computer together.
System Bus System Bus
CPU (Central Processing Unit) Also called a processor The brains of the computer Controls functions performed by other components Can perform up to 10s of billions of tasks per second Processor speed is measured in megahertz (MHz) or gigahertz (GHz) Well known manufactures are Intel and AMD
Single vs. Dual-Core Processor Processors become more efficient when they have multiple core s. Multiple core s allow the processor to execute multiple instructions at the same time.
CPU System Bus
CPU on Motherboard
RAM (Random Access Memory) This memory holds the data the computer is currently using Much faster to read and write from than the hard drive Temporary or volatile storage, this data is erased when the computer is shut down. Must save to hard drive Measured in megabytes (MB), or gigabytes (GB)
RAM System Bus
RAM on Motherboard
ROM (Read Only Memory) Memory which holds the startup instructions for the computer The instructions are permanently stored in this memory
ROM System Bus
RAM vs. ROM RAM stores instructions and data Temporary / Volatile storage Contains several memory cards or modules ROM Stores startup instructions Permanent storage
Input Output Processors Some computers rely on the CPU to handle on the input / output processing IO Processors relieve the CPU of the IO processing Let s the CPU focus and perform more efficiently on other operations
Input Output Processors System Bus
Data Storage RAM is useful for temporary storage (volatile) while the computer is running. Once the computer stops all data in RAM is gone We need permanent storage locations such as hard drive, cloud, DVD, or a flash drive
Hard Drive Nonvolatile storage (permanent) Holds programs and data Today s hard drives have capacities up to 8TB External hard drives can be connected to the computer via a port for additional/backup storage
How Hard Drives Work Data is saved on the disk in a pattern of magnetized spots spot = 1 Binary space = 0 Read write head can fail and lead to disk failures on your computer
Solid State Drive (SSD) A replacement for hard disk drives They do not have moving parts, so they are less prone to failure Run more efficiently, are less noisy, and emit less heat Exist in your computer, in a drive bay.
Cache This data is more accessible than the RAM This is the information you re program is currently using and must be readably accessible. Only a small amount of data can be stored here Think of when baking, the few ingredients you bring onto your small table that you want to use now
RAM The RAM holds the data and instructions your computer is currently using. Like the Cache this is volatile, and you need to store it away or it will be deleted when you close your computer Think of this as a temporary shelf, that isn t as accessible as the table, but is still easy to get to
Hard Disk Here is your permanent storage. All data that you want to save needs to go here. Think of this as your pantry, where you put all your items away at the end of cooking.
Flash Drives External solid state drives Can fit into your pocket
What do these storage amounts mean? Unit Size Meaning Byte 8 bits 1 character of data e.g. a Kilobyte (KB) 2 10 bytes = 1024 bytes Megabyte (MB) 2 20 bytes = about 1 million bytes Gigabyte (GB) 2 30 bytes = about 1 billion bytes Terabytes (TB) 2 40 bytes = about 1 trillion bytes Petabyte (PB) 2 50 bytes = about quadrillion bytes 1024 characters, about 1 page of plain text About 4 books About 4,500 books About 4.6 million books About 4.7 billion books
Review Here s a video of by How Stuff Works to review and visualize this pieces inside your computer http://computer.howstuffworks.com/23- computer-tour-video.htm
Inside your Computer
How Does the CPU Process? The CPU performs the following 4 commands in succession for every instruction Fetch Decode Execute Store
System Clock Acts as a metronome. Each tick (Clock Cycle) it executes the next instruction The clock speed is measured in Hertz (Hz)
CPU Instruction Cycle Clock Ticks 0 1 2 3 4 5 6 7 Instruction 1 Fetch Decode Execute Store Instruction 2 Fetch Decode Execute Store
Pipelining CPU works on more than one stage or instructions at a time Clock Ticks 0 1 2 3 4 5 6 Instruction 1 Fetch Decode Execute Store Instruction 2 Fetch Decode Execute Store Instruction 3 Fetch Decode Execute Store
Multiple Processors Having Dual or Multi-Core processors in one computer allow for multiple processors to work on the same problem at the same time However, the work needs to dividable such that there are independent problems for the processors to tackle
Desktop or Laptop Desktop Less Portable Less Expensive Harder to steal Easier to expand and upgrade Laptop More portable More expensive Easier to steal Harder to upgrade