About

Sim6502Java is a cycle-accurate simulation of the venerable MOS 6502 processor.

This package also includes simulations of the 6520 PIA and 6522 VIA Chips.

Most of this program is a straight 1:1 conversion from C to Java of the 6502 Simulator by Andre Weissflog, although it has been refactored to make it more object-oriented and more readable.

It passes the 6502 functional tests by Klaus Dormann, including the interrupt tests.

Usage

To use the simulator, instantiate the SIM6502 class.

Then set up an SIM6502Input object with the current state of the 6502 inputs.

Calling the Sim6502.tick() method will then simulate exactly one clock cycle of the processor. This method returns an Sim6502Output object with the state of all output lines of the simulated processor.

import de.innot.sim6502.Sim6502;
import de.innot.sim6502.Sim6502Input;
import de.innot.sim6502.Sim6502Output;

Sim6502 cpu = new Sim6502();

Sim6502Input input = new Sim6502Input();
Sim6502Output output;

...

while(true) {
	input.reset = true; // reset is active low, so set to true to go out of reset.
	output = cpu.tick(input);
	// handle output as required
}