First, the hardware
Computer Development:
| Decade | element | |
| The first generation | 1946~1958 | Tube |
| The second generation | 1959~1964 | Transistor |
| Third Generation | 1965~1970 | integrated circuit |
| Fourth Generation | 1971~？ | LSI |
The world's first computer: ENIAC
(1946.2, American University of Pennsylvania)
Von Neumann Theory (Hungarian-American mathematician)
① take binary
② stored program, program control
③ five components: computing, controller, memory, input devices, output devices
Operator: perform arithmetic and logic operations
Composition: ① arithmetic logic operation means (ALU) ② ③ accumulator and the status register general purpose registers
A central processing unit (the CPU) : by the arithmetic unit, a controller, and some memory.
Memory :
① memory (main memory): ROM (Read Only do not write will be lost), RAM (both read and write will be lost)
②CACHE: Cache
③ external memory (secondary memory): a magnetic disk (a flexible disk, a hard disk), an optical disk, a flash memory
Read and write speed: fast -> slow
CPU, Cache, memory, external memory
Computer hardware system:
Computer hardware systems:
1, the host
① CPU (arithmetic unit, a controller)
② memory (ROM, RAM)
2, the external device
① input devices - keyboard, mouse, microphone, a scanner, touch screen
② output devices - monitors, printers, projectors, plotter, speakers
③ external memory - a floppy drive, hard drive, optical disk drive
Turing (UK) "Turing test," the founder of computer logic (AI)
The computer industry's highest award: the Turing Award
Second, the software
Computer Software: ① system software DOS, Window95 / 98/2000, Unix, Linux, WindowsNT
② application software word processing software, spreadsheet software, database management software
Programming language (computer language)
① low-level language (machine language, assembly language)
② high-level language: Basic, Pascal, Fortran, C / C ++ / C #, Jave, Lisp, Prolog
Third, the number of encoding system
Binary (B) octal (O) decimal (D) in hexadecimal (H)
① two, eight, hexadecimal, decimal turn - right by summing expansion
② turn binary decimal
The integer part of: dividing inverse modulo Method 2
Decimal part: 2 multiplied by the forward rounding method
③ two to eight 3: 1 eight to two 1: 3
Two to sixteen 4: 1 sixteen to two 1: 4
The original code, anti-code and complement
① positive: the sign bit (MSB) 0
The original code, anti-code and complement the same
② negative: the sign bit (MSB) is 1
Anti-code: you original code except the sign bit inverted
Complement: a plus-minus
Fourth, networking basics
The main function of computer networks: sharing resources
Computer network consisting of: ① ② network hardware network software
Network servers: characterized by primary and secondary storage capacity and high processing speed
Network Category:
① communication distance divided by: a local area network (LAN) Metropolitan Area Network (MAN) wide area network (WAN)
② Press network topology point: star network, ring network, bus network, tree, mesh
Network protocol
①OSI
| 7 | Application layer | Data transfer between the host is responsible for: high-rise | Customer service |
| 6 | Presentation layer | Data conversion, encryption, text compression and | |
| 5 | Session Layer | ||
| 4 | Transport Layer | Bottom: responsible for network data transmission | End to end, the transmission unit: packet (segment) |
| 3 | Network layer | Routing, the interconnection network, a transmission unit: Packet | |
| 2 | data link layer | Reliable transmission point, the transmission unit: a frame | |
| 1 | Physical Layer | A transmission unit: binary stream (bit stream) |
OSI model is only an ideal conceptual model.
②TCP: Transmission Control Protocol
IP: Internet Protocol
protocol:
FTP: File Transfer Protocol
Telnet: Telnet protocol
HTTP: Hypertext Transfer Protocol
HTML: HTML
IMAP: Message Access Protocol
POP3: Post Office Protocol
SMTP: Simple Mail Transfer Protocol
ARP: ARP