Basic start of 6502 chip emulation. Mostly empty.

src/6502.js

+/*
+ * Emulate a basic 6502 (MOS) chip.
+ */
+
+// Registers
+var PC = 0;   // Program Counter (16 bit)
+var IRQ = 0;  // IRQ interrupt address code (16 bit)
+var SR = 0;   // Status Register (8 bit)
+var XR = 0;   // X Register (8 bit)
+var YR = 0;   // Y Register (8 bit)
+var AR = 0;   // Accumulator Register (8 bit)