为什么要学操作系统

帅

什么是操作系统

为程序提供服务的算操作系统

硬件和软件的中间层

广义： 为人提供服务都算，せかい（sekai）是一个操作系统

一点数电

数电都讲点什么

一个简单的公理系统（导线，时钟，逻辑门，触发器），凭这些可以计算机世界上一切东西
能支撑非常复杂的数字系统设计
1. 导线：一直有电平的高或低
2. 触发器（filp-flop）:可存储1bit的内容，先锁存住，到时钟周期的时候再把值写进去。就如verilog中的reg

与非门

先定义与非门

1 2	// 先算与门再算非门 #define NAND(X,Y) (!((X) && (Y)))

构造NOT gate AND gate OR gate

NOT gate

1	#define NOT(X) (NAND(X,1))

AND gate
1
#define AND(X,Y) (NOT(NAND(X,Y)))

OR gate

1	#define OR(X,Y) (NAND(NOT(X),NOT(Y)))

数电＋一点代码

C语言写数字电路，后用python做可视化，用管道符连接即可

#include <logisim.h>
#include <stdio.h>

// Wire and registers in the circuit
wire X, Y, X1, Y1, A, B, C, D, E, F, G;
reg b1 = {.in = &X1, .out = &X};
reg b0 = {.in = &Y1, .out = &Y};

int main() {
    CLOCK_CYCLE {
        // 1. Propagate wire values through combinatorial logic
        X1 = AND(NOT(X), Y);
        Y1 = NOT(OR(X, Y));
        A = D = E = NOT(Y);
        B = 1;
        C = NOT(X);
        F = Y1;
        G = X;

        // 2. Edge triggering: Lock values in the flip-flops
        b0.value = *b0.in;
        b1.value = *b1.in;
        *b0.out = b0.value;
        *b1.out = b1.value;

        // 3. End of a cycle; display output wire values
        #define PRINT(X) printf(#X " = %d; ", X)
        PRINT(A);
        PRINT(B);
        PRINT(C);
        PRINT(D);
        PRINT(E);
        PRINT(F);
        PRINT(G);
        printf("\n");
        fflush(stdout);
        sleep(1);
    }
}

import fileinput

TEMPLATE = '''
   AAAAAAAAAAAA
   FF        BB
   FF        BB
   FF        BB
   FF        BB
   FEGGGGGGGGBC
   EE        CC
   EE        CC
   EE        CC
   EE        CC
   DDDDDDDDDDDD
'''

# These are ANSI Escape Codes
CLEAR = '\033[2J\033[1;1f'  # Clear screen and move cursor to top-left
WHITE = '\033[37m░\033[0m'  # A white block
BLACK = '\033[31m█\033[0m'  # A black block

for line in fileinput.input():
    # Execute the input line (like "A=0; B=1; ...") as Python code; the
    # variables A, B, ... will be stored in ctx.
    exec(line, (ctx := {}))

    # Initialize the display with a clear screen and the template.
    disp = CLEAR + TEMPLATE

    for ch in 'ABCDEFG':
        # Determine the block color.
        block = {
            0: WHITE,
            1: BLACK,
        }.get(ctx.get(ch, 0), '?')

        # Replace each character in the template with its block.
        disp = disp.replace(ch, block)

    print(disp)