Introduction to Computers
1. Computer: a good tool to assist the human brain
The essence of a computer: an output tool that processes input information
1. Five major units
-CPU
The CPU is a chip with specific functions, including an arithmetic logic unit and a control unit. The arithmetic logic unit is responsible for program operations and logical judgment, while the control unit mainly coordinates the work between peripheral components and individual units.
-Main memory
container
-Input unit
keyboard, mouse
-Output unit
screen, printer
2. Types of CPU
1. Reduced Instruction Set Computing (RISC)
The running time of each instruction is very short, the completion action is simple, and the execution performance of the instruction is better.
When dealing with complex things, multiple instructions are required to complete it.
SUN's SPARC, academic field, financial system
IBM's Power Architecture, Sony's PS3
ARM: mobile phones, PDA navigation, network equipment
2. Complex Instruction Set Computing (RISC)
Each small instruction can perform some lower-level hardware operations. The number of instructions is large and complex, and the length of each instruction is not the same.
There are CPUs with x86 architecture such as AMD, Intel, VIA, etc.
3. Interface equipment
motherboard
Storage device: hard disk, floppy disk, optical disk, tape
Display device: Display adapter, very important for 3D games
Network device: network card
4. Operational process
RAM（random access memory）
ROM（Read-Only Memory）
-CPU
The brain processes all kinds of data
-Main memory
recording block of brain
-harddisk
Memory blocks in the brain
-Motherboard
nervous system
-Various interfaces
hands, feet, skin, eyes
-Display adapter
images in head
-Power Supplier
heart, power supply
5. Computer classification
Classification by computer complexity and computing power
-supercomputer
Features: fast calculation speed, high maintenance cost
Purpose: National defense and military, weather prediction, space technology, simulation fields
-Mainframe computers
There are several high-speed CPUs
Mainframe of large enterprises, national full volume exchange, large enterprise data server
-Mini computer
Support multiple users
Can be placed in the workplace
Used for scientific research, engineering analysis, and factory process management
-workstation
Academic research and engineering analysis
-Microcomputer
Personal computer, small and cheap
6. Common units of computer capacity and speed
1Byte=8bit
1KB=1024B
1MB=1024KB
1GB=1024MB
speed unit
MHz and GHz
Hz means one-second
Mbps is Mbits per second
How many Mbits per second?
2. Personal computer architecture and interface devices
Intel motherboard chip
The chip is usually divided into two bridges to control communication between components
-Northbridge
Responsible for linking faster CPU, main memory and display adapter
-South Bridge
Responsible for peripheral interfaces with slow link speeds, including hard drives, USB, and network cards.
AMD motherboard chips
The main memory communicates directly with the CPU without going through the North Bridge.
2.Inter--Gigabyte GA-X48-DQ6
Main components
CPU, main memory, disk devices, bus chipsets, display adapter interfaces and other adapter cards
1.CPU
Distinguished according to microinstruction set
According to the frequency, that is, the number of operations per second, the frequency can be divided into external frequency and multiplication frequency.
FSB
It is the speed at which data is transferred between the CPU and external components.
Frequency multiplier
It is a multiple used internally by the CPU to accelerate work performance.
FSB*multiplier is the frequency speed of the CPU
For example, frequency 3G = FSB 333M * multiplier 9
Overclocking
It is to modify the external frequency to achieve the goal of increasing the frequency.
-Main memory
The function of the bus communicates between the CPU and the main memory. Generally, the motherboard chip has a north and south bridge.
front side bus speed
Frequencies supported by Northbridge
bus width
width of each transfer
Bus bandwidth = FSB * bus width
The amount of data that the CPU can process at a time becomes the word group size.
32-bit CPU can only support up to 4G memory--2^32BYTE
CPU level
Inter levels include i368, i586, and 686. The program must correspond to the CPU.
2.Memory
RAM
-Random access memory can only be recorded and used when the power is on, and the data disappears after the power is turned off.
Dual channel design
Increase the data width of the main memory and combine the two main memories together, one 64 and two 128
The relationship between CPU frequency and main memory
The FSB of the CPU and the main memory should be the same.
SRAM
Second layer cache concept, implemented through SRAM
CMOS
A chip that records whether the network card and display adapter are started and parameters, requires an additional battery
ROM
BIOS program is recorded on ROM
3. Display adapter VGA (Video Graphics Array)
Display focus is on resolution and color depth
GPU
CPU on graphics card
4. Hard drives and storage devices
storage device
Hard disk, floppy disk, MO, CD, DVD
The physical components of a hard drive
Circular disk platter, robotic arm, disk read head and spindle motor
data on hard drive
There seems to be multiple pie areas drawn in concentric circles on the entire disk.
Minimum storage unit sector size 512B
Track: a circle made up of sectors
Magnetic cylinder: the same track for all disks
Disk storage
The number of headers * the number of magnetic columns each header is responsible for * the number of sectors contained in each magnetic column * the capacity of the sectors
Transmission interface
Connection between hard disk and host system
HOURS GO
IDE interface
Electronic integrated drive is a hard drive that integrates the " hard disk controller " and the "disk body"
133MB
SATA interface
300MB
SCSI interface
Interfaces commonly used on workstations
Purchase and operation instructions
When adding a hard disk to the host, you need to consider
1.Interface
2.Capacity
3. Buffer memory
4.Rotation speed
5. Operation instructions
5.PIC adapter card
Network card interface
6. Motherboard
1.Main members
North and South Bridge
2. Chipset functions
Choose the right chip component combination
3. Device I/O address and IRQ interrupt channel
address of each device
IRQ is the path from the device to the CPU
-Interface for connecting interface devices
PS
USB
Sound and microphone
RJ-45
A few other bites
7.Power supply
1. Energy conversion rate
The motherboard consumes 250W power and the power supply consumes 320W.
Efficiency: 250/320=0.78
2.Connection interface
20pin and 24pin
8.Purchase instructions
When considering the barrel effect, you can’t just consider the CPU
3. Data representation
1. Digital system
Power on is 1, power off is 0
Convert binary to decimal
Convert decimal to binary
2. Text encoding system
1Byte=8bit, which is 8 binary bits
Each symbol in the ASCII system occupies 1bytes of records
Chinese characters are 2 bytes and use the Unicode encoding system.
3. Software program operation
System software and applications
4. Mechanical program and compiler program
Operations and logical judgments are implemented through microinstruction sets
-Requires knowledge of machine language
-Need to understand the relevant functions of all hardware
-The program is not portable
-The program is transferable
Solution
Compiler
5. Operating system
Drivers for all hardware and provides a reference interface for developing software
-Operating system core
Allows the CPU to start judging logical AND operation values
Let main memory start loading/alone data
Allow the hard drive to begin being accessed
Allow the network card to start transferring data
System call
c program function
-Core functions
About resource allocation and management related to computer systems
--System call interface
Can call the core
-Program management
multitasking environment
Manage multiple tasks
Memory management
To manage system memory, the kernel usually provides the function of virtual memory. When the memory is insufficient, it provides the function of memory replacement.
File system management
Data input and output, support for different file formats,
Device driver
Hardware management, device drivers
Loadable modules can edit drivers into modules
Operating system and drivers
The operating system provides an interface to install drivers and control software.
6.Applications
Application programs are software developed by referring to the development interface provided by the operating system.