Electricity: Voltage. Gate: A signal enters the gate at a certain voltage. The gate performs operations on it, and sends it out was a new signal.

Transcription

1 Hardware CSCE 101

2 Electricity: Voltage Gate: A signal enters the gate at a certain voltage. The gate performs operations on it, and sends it out was a new signal. The signals voltage will either be between 0-2 (binary 0), or 2-5 (binary 1) So Binary data is travelling around our computer as a voltage signal

3 Gates There are different types of gates, to accomplish different types of logic. NOT Gate, which negates the signal AND Gate, which takes two signals and combines them

4 Basic Logic Operators AND OR XOR NOT Unary Binary Y = a b, Y is 1 if and only if a=b=1 Y = a+b, Y is 1 if either a=1 or b=1 Y = a, Y is 1 if a=0 Y = a b, Y is 0 if both a and b are same, 1 if they are different

5 Basic Logic Operators (cont.) 1-bit logic AND resembles binary multiplication: 0 0 = 0, 0 1 = 0, 1 0 = 0, 1 1 = 1 1-bit logic OR resembles binary addition, except for one operation: = 0, = 1, = 1, = 1 ( 10 2 ) Boolean Algebra PJF - 5

6 Truth Tables for logic operators Truth table: tabular form that uniguely represents the relationship between the input variables of a function and its output 2-Input AND 2-Input OR A B Y=A B A B Y=A+B NOT A Y=A Boolean Algebra PJF - 6

7 Logic Gates Logic gates are abstractions of electronic circuit components that operate on one or more input signals to produce an output signal. 2-Input AND 2-Input OR NOT (Inverter) A B Y = A B Y A Y A Y B Y = A+B Y = A Boolean Algebra PJF - 7

8 Logic Gates

9 1 Bit Addition Let A and B are two inputs to be added SUM = A B CARRY = A B Boolean Algebra PJF - 9

10 Integrated Circuits An integrated circuit is a piece of silicon on which multiple gates have been embedded. (CSI) The integrated circuit consists of pins which are the input and output to gates. The CPU (Central Processing Unit) is an advanced integrated circuit with a large number of pins

11 Computer Functions Input Process Store Output

12 Computer Functions Input: Gathers data often from user entry Process: Takes data performs instructions on it, to change it into the desired information Storage: Saves data for use later Output: Displays data in a human readable form

13 Programmable data processor model A program is a set of instructions that tells the computer what to do with data. A program is a set of instructions written in a computer language. The output data depend on the combination of two factors: the input data and the program.

14 Same program, different data

15 Same data, different programs

16 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 10 KB = about 1 million bytes 2 10 MB = about 1 billion bytes 2 10 GB = about 1 trillion bytes 2 10 PB = about quadrillion bytes

17 Computer Hardware Hardware refers to the physical parts of the computer that can be touched. Examples: mouse keyboard graphics card hard disk drive

18 Input Devices Devices which let you enter data into the computer keyboard mouse / touchpad microphone scanner game controller stylus

19 Output Devices Sends data out from the computer to be seen in a human readable way: text, pictures, sound, Examples: Monitor Printer GPS Speakers

20 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

21 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

22 System Bus Communication link that connects all the different parts of the computer together.

23 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

24 CPU on Motherboard CPU

25 Von Neumann Architecture Computers built on the von Neumann model divide the computer hardware into four subsystems: memory, arithmetic logic unit, control unit, and input/output Fig: The von Neumann model

26 von Neumann Architecture: Four subsystems Memory Memory is the storage area Generally, RAM Arithmetic logic unit (ALU) The ALU is where calculation and logical operations take place. Like Addition, Subtraction Control unit The control unit controls the operations of the memory, ALU, and the input/output subsystem. Input/output The input subsystem accepts input data and the program from outside the computer. The output subsystem sends the result of processing to the outside.

27 The stored program concept The von Neumann model states that the program must be stored in memory. This is totally different from the architecture of early computers in which only the data was stored in memory: the programs for their task was implemented by manipulating a set of switches or by changing the wiring system. The memory of modern computers hosts both a program and its corresponding data. This implies that both the data and programs should have the same format, because they are stored in memory. In fact, they are stored as binary patterns in memory a sequence of 0s and 1s.

28 Figure Program and data in memory

29 How Does the CPU Process? The Fetch-Execute Cycle The CPU performs the following commands in succession for every instruction Fetch: Get next instruction Decode: Determine what type of instruction Get Data: If external data is needed, it retrieves it Execute: Perform the operation Store: Save result

30

31 System Clock Acts as a metronome. Each tick (Clock Cycle) it executes the next instruction The clock speed is measured in Hertz (Hz)

32 CPU Instruction Cycle Clock Ticks Instruction 1 Fetch Decode Execute Store Instruction 2 Fetch Decode Execute Store

33 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.

34 32bit word vs. 64 bit The word size is describing the size of the instructions which can be executed 32 Bit 64 Bit Fetch Cookies Fetch Milk Eat Cookies Eat Milk Fetch Cookies & Milk Eat Cookies & Milk

35 Memory The computer associates locations (addresses) with contents. Just like your own brain, it has a certain spot where it stores certain information. Address Contents

36 RAM (Random Access Memory) This memory holds the data the computer is currently using It is called Random Access because you can retrieve any piece of data at any time, you do not need to sequentially retrieve it 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)

37 RAM on Motherboard

38 ROM (Read Only Memory) Memory which holds the startup instructions for the computer The instructions are permanently stored in this memory Non-volatile

39 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

40 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

41 How Hard Drives Work Data is saved on the disk in a pattern of magnetized spots Read write head can fail and lead to disk failures on your computer

42 Hard Disk Organization When you save information to the hard drive it places the info around the tracks in sectors.

43 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.

44 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

45 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.

46 Flash Drives External solid state drives Can fit into your pocket

47 Review Here s a video of by How Stuff Works to review and visualize this pieces inside your computer er-tour-video.htm

48 Inside your Computer

49 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