1  #include <stdio.h>
 2  #include <stdlib.h>
 3  
 4  // http://www.obelisk.me.uk/6502/
 5  
 6  using Byte = unsigned char;
 7  using Word = unsigned short;
 8  
 9  using u32 = unsigned int;
10  
11  struct Mem {
12    static constexpr u32 MAX_MEM = 1024 * 64;
13    Byte Data[MAX_MEM];
14  
15    void Initialise() {
16      for (u32 i = 0; i < MAX_MEM; i++) {
17        Data[i] = 0;
18      }
19    }
20  };
21  
22  struct CPU {
23    Word PC; // program counter
24    Word SP; // stack pointer
25  
26    Byte A, X, Y; // registers
27  
28    Byte C : 1; // status flag
29    Byte Z : 1; // status flag
30    Byte I : 1; // status flag
31    Byte D : 1; // status flag
32    Byte B : 1; // status flag
33    Byte V : 1; // status flag
34    Byte N : 1; // status flag
35  
36    void Reset(Mem &memory) {
37      PC = 0xFFFC;
38      SP = 0x0100;
39      C = Z = I = D = B = V = N = 0;
40      A = X = Y = 0;
41      memory.Initialise();
42    }
43  };
44  
45  int main() {
46    Mem mem;
47    CPU cpu;
48    cpu.Reset(mem);
49    return 0;
50  }