An emulation of the 6502 CPU as produced by WDC (WDC 65C02).

The CPU has 6 registers, 3 of which are of general use.

• a - 8-bit accumulator
• x - 8-bit general use
• y - 8-bit general use
• sp - 8-bit stack pointer
• p - 8-bit processor status flags. The bits represent, from MSB to LSB:
  • N - Negative
  • V - Overflow
  • - - Unused
  • B - Break command
  • D - Decimal mode
  • I - Interrupt disable
  • Z - Zero
  • C - Carry
• pc - 16-bit program counter

Special memory addresses include:

• $FFFA - non masking interrupt
• $FFFC - reset
• $FFFE - IRQ