clock() {
		// Each instruction requires a variable number of clock cycles to execute.
		// In my emulation, I only care about the final result and so I perform
		// the entire computation in one hit. In hardware, each clock cycle would
		// perform "microcode" style transformations of the CPUs state.
		//
		// To remain compliant with connected devices, it's important that the
		// emulation also takes "time" in order to execute instructions, so I
		// implement that delay by simply counting down the cycles required by
		// the instruction. When it reaches 0, the instruction is complete, and
		// the next one is ready to be executed.
		if (this.cycles === 0) {
			// Read next instruction byte. This 8-bit value is used to index
			// the translation table to get the relevant information about
			// how to implement the instruction
			this.opcode = this.read(this.pc) || 0;

			// Always set the unused status flag bit to 1
			this.SetFlag(FLAGS6502.U, true);

			// Increment program counter, we read the opcode byte
			this.pc++;

			// Get Starting number of cycles
			this.cycles = this.lookup[this.opcode].cycles;

			// Perform fetch of intermmediate data using the
			// required addressing mode
			let additional_cycle1 = (this.lookup[this.opcode].addrmode).bind(this)();

			// Perform operation
			let additional_cycle2 = (this.lookup[this.opcode].operate).bind(this)();

			// The addressmode and opcode may have altered the number
			// of cycles this instruction requires before its completed
			this.cycles += (additional_cycle1 & additional_cycle2);

			// Always set the unused status flag bit to 1
			this.SetFlag(FLAGS6502.U, true);

			/*#ifdef LOGMODE
			// This logger dumps every cycle the entire processor state for analysis.
			// This can be used for debugging the emulation, but has little utility
			// during emulation. Its also very slow, so only use if you have to.
			if (logfile == nullptr)	logfile = fopen("olc6502.txt", "wt");
			if (logfile != nullptr)
			{
				fprintf(logfile, "%10d:%02d PC:%04X %s A:%02X X:%02X Y:%02X %s%s%s%s%s%s%s%s STKP:%02X\n",
					clock_count, 0, log_pc, "XXX", a, x, y,
					GetFlag(N) ? "N" : ".",	GetFlag(V) ? "V" : ".",	GetFlag(U) ? "U" : ".",
					GetFlag(B) ? "B" : ".",	GetFlag(D) ? "D" : ".",	GetFlag(I) ? "I" : ".",
					GetFlag(Z) ? "Z" : ".",	GetFlag(C) ? "C" : ".",	stkp);
			}
			#endif*/
		}

		// Increment global clock count - This is actually unused unless logging is enabled
		// but I've kept it in because its a handy watch variable for debugging
		this.clock_count++;

		// Decrement the number of cycles remaining for this instruction
		this.cycles--;
	}
// Perform one clock cycles worth of emulation
Perform one clock cycles worth of emulation
Perform one clock cycles worth of emulation
clock() {
		 To remain compliant with connected devices, it's important that the
		 emulation also takes "time" in order to execute instructions, so I
		 implement that delay by simply counting down the cycles required by
		 the instruction. When it reaches 0, the instruction is complete, and
		 the next one is ready to be executed.
		if (this.cycles === 0) {
			 Read next instruction byte. This 8-bit value is used to index
			 the translation table to get the relevant information about
			 how to implement the instruction
			this.opcode = this.read(this.pc) || 0;
			 Always set the unused status flag bit to 1
			this.SetFlag(FLAGS6502.U, true);
			 Increment program counter, we read the opcode byte
			this.pc++;
			 Get Starting number of cycles
			this.cycles = this.lookup[this.opcode].cycles;
			 Perform fetch of intermmediate data using the
			 required addressing mode
			let additional_cycle1 = (this.lookup[this.opcode].addrmode).bind(this)();
			 Perform operation
			let additional_cycle2 = (this.lookup[this.opcode].operate).bind(this)();
			 The addressmode and opcode may have altered the number
			 of cycles this instruction requires before its completed
			this.cycles += (additional_cycle1 & additional_cycle2);
			 Always set the unused status flag bit to 1
			this.SetFlag(FLAGS6502.U, true);
			/*#ifdef LOGMODE
			 This logger dumps every cycle the entire processor state for analysis.
			 This can be used for debugging the emulation, but has little utility
			 during emulation. Its also very slow, so only use if you have to.
			if (logfile == nullptr)	logfile = fopen("olc6502.txt", "wt");
			if (logfile != nullptr)
			{
				fprintf(logfile, "%10d:%02d PC:%04X %s A:%02X X:%02X Y:%02X %s%s%s%s%s%s%s%s STKP:%02X\n",
					clock_count, 0, log_pc, "XXX", a, x, y,
					GetFlag(N) ? "N" : ".",	GetFlag(V) ? "V" : ".",	GetFlag(U) ? "U" : ".",
					GetFlag(B) ? "B" : ".",	GetFlag(D) ? "D" : ".",	GetFlag(I) ? "I" : ".",
					GetFlag(Z) ? "Z" : ".",	GetFlag(C) ? "C" : ".",	stkp);
			}
			#endif*/
		}
		 Increment global clock count - This is actually unused unless logging is enabled
		 but I've kept it in because its a handy watch variable for debugging
		this.clock_count++;
		 Decrement the number of cycles remaining for this instruction
		this.cycles--;
	}
clock ( ) { if ( this . cycles === 0 ) { this . opcode = this . read ( this . pc ) || 0 ; this . SetFlag ( FLAGS6502 . U , true ) ; this . pc ++ ; this . cycles = this . lookup [ this . opcode ] . cycles ; let additional_cycle1 = ( this . lookup [ this . opcode ] . addrmode ) . bind ( this ) ( ) ; let additional_cycle2 = ( this . lookup [ this . opcode ] . operate ) . bind ( this ) ( ) ; this . cycles += ( additional_cycle1 & additional_cycle2 ) ; this . SetFlag ( FLAGS6502 . U , true ) ; } this . clock_count ++ ; this . cycles -- ; }
Perform one clock cycles worth of emulation
Perform one clock cycles worth of emulation
// Each instruction requires a variable number of clock cycles to execute. // In my emulation, I only care about the final result and so I perform // the entire computation in one hit. In hardware, each clock cycle would // perform "microcode" style transformations of the CPUs state. // // To remain compliant with connected devices, it's important that the // emulation also takes "time" in order to execute instructions, so I // implement that delay by simply counting down the cycles required by // the instruction. When it reaches 0, the instruction is complete, and // the next one is ready to be executed. // Read next instruction byte. This 8-bit value is used to index // the translation table to get the relevant information about // how to implement the instruction // Always set the unused status flag bit to 1 // Increment program counter, we read the opcode byte // Get Starting number of cycles // Perform fetch of intermmediate data using the // required addressing mode // Perform operation // The addressmode and opcode may have altered the number // of cycles this instruction requires before its completed // Always set the unused status flag bit to 1 /*#ifdef LOGMODE
			// This logger dumps every cycle the entire processor state for analysis.
			// This can be used for debugging the emulation, but has little utility
			// during emulation. Its also very slow, so only use if you have to.
			if (logfile == nullptr)	logfile = fopen("olc6502.txt", "wt");
			if (logfile != nullptr)
			{
				fprintf(logfile, "%10d:%02d PC:%04X %s A:%02X X:%02X Y:%02X %s%s%s%s%s%s%s%s STKP:%02X\n",
					clock_count, 0, log_pc, "XXX", a, x, y,
					GetFlag(N) ? "N" : ".",	GetFlag(V) ? "V" : ".",	GetFlag(U) ? "U" : ".",
					GetFlag(B) ? "B" : ".",	GetFlag(D) ? "D" : ".",	GetFlag(I) ? "I" : ".",
					GetFlag(Z) ? "Z" : ".",	GetFlag(C) ? "C" : ".",	stkp);
			}
			#endif*/ // Increment global clock count - This is actually unused unless logging is enabled // but I've kept it in because its a handy watch variable for debugging // Decrement the number of cycles remaining for this instruction