class TestSystemFunctionOperations(unittest.TestCase):
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
def test_BRK(self):
self.cpu.program_counter = 0x1000
self.memory.rom.load(0xFFFE, [0x00, 0x20])
status = self.cpu.status_as_byte()
self.cpu.BRK()
self.assertEqual(self.cpu.program_counter, 0x2000)
self.assertEqual(self.cpu.break_flag, 1)
self.assertEqual(self.memory.read_byte(None, self.cpu.STACK_PAGE + self.cpu.stack_pointer + 1), status)
self.assertEqual(self.memory.read_byte(None, self.cpu.STACK_PAGE + self.cpu.stack_pointer + 2), 0x01)
self.assertEqual(self.memory.read_byte(None, self.cpu.STACK_PAGE + self.cpu.stack_pointer + 3), 0x10)
def test_RTI(self):
self.memory.write_byte(None, self.cpu.STACK_PAGE + 0xFF, 0x12)
self.memory.write_byte(None, self.cpu.STACK_PAGE + 0xFE, 0x33)
self.memory.write_byte(None, self.cpu.STACK_PAGE + 0xFD, 0x20)
self.cpu.stack_pointer = 0xFC
self.cpu.RTI()
self.assertEqual(self.cpu.program_counter, 0x1233)
self.assertEqual(self.cpu.status_as_byte(), 0x20)
def test_NOP(self):
self.cpu.NOP()
class TestSystemFunctionOperations(unittest.TestCase):
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
def test_BRK(self):
self.cpu.program_counter = 0x1000
self.memory.rom.load(0xFFFE, [0x00, 0x20])
status = self.cpu.status_as_byte()
self.cpu.BRK()
self.assertEqual(self.cpu.program_counter, 0x2000)
self.assertEqual(self.cpu.break_flag, 1)
self.assertEqual(
self.memory.read_byte(
None, self.cpu.STACK_PAGE + self.cpu.stack_pointer + 1),
status)
self.assertEqual(
self.memory.read_byte(
None, self.cpu.STACK_PAGE + self.cpu.stack_pointer + 2), 0x01)
self.assertEqual(
self.memory.read_byte(
None, self.cpu.STACK_PAGE + self.cpu.stack_pointer + 3), 0x10)
def test_RTI(self):
self.memory.write_byte(None, self.cpu.STACK_PAGE + 0xFF, 0x12)
self.memory.write_byte(None, self.cpu.STACK_PAGE + 0xFE, 0x33)
self.memory.write_byte(None, self.cpu.STACK_PAGE + 0xFD, 0x20)
self.cpu.stack_pointer = 0xFC
self.cpu.RTI()
self.assertEqual(self.cpu.program_counter, 0x1233)
self.assertEqual(self.cpu.status_as_byte(), 0x20)
def test_NOP(self):
self.cpu.NOP()
class TestJumpCallOperations(unittest.TestCase):
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
def test_JMP(self):
self.cpu.JMP(0x1000)
self.assertEqual(self.cpu.program_counter, 0x1000)
def test_JSR(self):
self.cpu.program_counter = 0x1000
self.cpu.JSR(0x2000)
self.assertEqual(self.cpu.program_counter, 0x2000)
self.assertEqual(
self.memory.read_byte(
None, self.cpu.STACK_PAGE + self.cpu.stack_pointer + 1), 0xFF)
self.assertEqual(
self.memory.read_byte(
None, self.cpu.STACK_PAGE + self.cpu.stack_pointer + 2), 0x0F)
def test_RTS(self):
self.memory.write_byte(None, self.cpu.STACK_PAGE + 0xFF, 0x12)
self.memory.write_byte(None, self.cpu.STACK_PAGE + 0xFE, 0x33)
self.cpu.stack_pointer = 0xFD
self.cpu.RTS()
self.assertEqual(self.cpu.program_counter, 0x1234)
def test_JSR_and_RTS(self):
self.cpu.program_counter = 0x1000
self.cpu.JSR(0x2000)
self.assertEqual(self.cpu.program_counter, 0x2000)
self.cpu.RTS()
self.assertEqual(self.cpu.program_counter, 0x1000) # @@@
class TestStackOperations(unittest.TestCase):
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
def test_TSX(self):
s = self.cpu.stack_pointer
self.cpu.TSX()
self.assertEqual(self.cpu.x_index, s)
# @@@ check NZ?
def test_TXS(self):
x = self.cpu.x_index
self.cpu.TXS()
self.assertEqual(self.cpu.stack_pointer, x)
def test_PHA_and_PLA(self):
self.cpu.accumulator = 0x00
self.cpu.PHA()
self.cpu.accumulator = 0x01
self.cpu.PHA()
self.cpu.accumulator = 0xFF
self.cpu.PHA()
self.assertEqual(self.cpu.accumulator, 0xFF)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.sign_flag, 0)
self.cpu.PLA()
self.assertEqual(self.cpu.accumulator, 0xFF)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.sign_flag, 1)
self.cpu.PLA()
self.assertEqual(self.cpu.accumulator, 0x01)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.sign_flag, 0)
self.cpu.PLA()
self.assertEqual(self.cpu.accumulator, 0x00)
self.assertEqual(self.cpu.zero_flag, 1)
self.assertEqual(self.cpu.sign_flag, 0)
def test_PHP_and_PLP(self):
p = self.cpu.status_as_byte()
self.cpu.PHP()
self.cpu.status_from_byte(0xFF)
self.cpu.PLP()
self.assertEqual(self.cpu.status_as_byte(), p)
class Test6502Bugs(unittest.TestCase):
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
def test_zero_page_x(self):
self.cpu.x_index = 0x01
self.memory.load(0x1000, [0x00, 0x7F, 0xFF])
self.cpu.program_counter = 0x1000
self.assertEqual(self.cpu.zero_page_x_mode(), 0x01)
self.assertEqual(self.cpu.zero_page_x_mode(), 0x80)
self.assertEqual(self.cpu.zero_page_x_mode(), 0x00)
def test_indirect(self):
self.memory.load(0x20, [0x00, 0x20])
self.memory.load(0x00, [0x12])
self.memory.load(0xFF, [0x34])
self.memory.load(0x100, [0x56])
self.memory.load(0x1000, [0x20, 0x20, 0xFF, 0xFF, 0x00, 0x45, 0x23])
self.memory.load(0x2000, [0x05])
self.memory.load(0x1234, [0x05])
self.memory.load(0x2345, [0x00, 0xF0])
self.cpu.program_counter = 0x1000
self.cpu.x_index = 0x00
self.cpu.LDA(self.cpu.indirect_x_mode())
self.assertEqual(self.cpu.accumulator, 0x05)
self.cpu.y_index = 0x00
self.cpu.LDA(self.cpu.indirect_y_mode())
self.assertEqual(self.cpu.accumulator, 0x05)
self.cpu.y_index = 0x00
self.cpu.LDA(self.cpu.indirect_y_mode())
self.assertEqual(self.cpu.accumulator, 0x05)
self.cpu.x_index = 0x00
self.cpu.LDA(self.cpu.indirect_x_mode())
self.assertEqual(self.cpu.accumulator, 0x05)
self.cpu.x_index = 0xFF
self.cpu.LDA(self.cpu.indirect_x_mode())
self.assertEqual(self.cpu.accumulator, 0x05)
self.assertEqual(self.cpu.indirect_mode(), 0xF000)
class TestStatusFlagOperations(unittest.TestCase):
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
def test_CLC(self):
self.cpu.carry_flag = 1
self.cpu.CLC()
self.assertEqual(self.cpu.carry_flag, 0)
def test_CLD(self):
self.cpu.decimal_mode_flag = 1
self.cpu.CLD()
self.assertEqual(self.cpu.decimal_mode_flag, 0)
def test_CLI(self):
self.cpu.interrupt_disable_flag = 1
self.cpu.CLI()
self.assertEqual(self.cpu.interrupt_disable_flag, 0)
def test_CLV(self):
self.cpu.overflow_flag = 1
self.cpu.CLV()
self.assertEqual(self.cpu.overflow_flag, 0)
def test_SEC(self):
self.cpu.carry_flag = 0
self.cpu.SEC()
self.assertEqual(self.cpu.carry_flag, 1)
def test_SED(self):
self.cpu.decimal_mode_flag = 0
self.cpu.SED()
self.assertEqual(self.cpu.decimal_mode_flag, 1)
def test_SEI(self):
self.cpu.interrupt_disable_flag = 0
self.cpu.SEI()
self.assertEqual(self.cpu.interrupt_disable_flag, 1)
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
class Test6502Bugs(unittest.TestCase):
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
def test_zero_page_x(self):
self.cpu.x_index = 0x01
self.memory.load(0x1000, [0x00, 0x7F, 0xFF])
self.cpu.program_counter = 0x1000
self.assertEqual(self.cpu.zero_page_x_mode(), 0x01)
self.assertEqual(self.cpu.zero_page_x_mode(), 0x80)
self.assertEqual(self.cpu.zero_page_x_mode(), 0x00)
def test_indirect(self):
self.memory.load(0x20, [0x00, 0x20])
self.memory.load(0x00, [0x12])
self.memory.load(0xFF, [0x34])
self.memory.load(0x100, [0x56])
self.memory.load(0x1000, [0x20, 0x20, 0xFF, 0xFF, 0x00, 0x45, 0x23])
self.memory.load(0x2000, [0x05])
self.memory.load(0x1234, [0x05])
self.memory.load(0x2345, [0x00, 0xF0])
self.cpu.program_counter = 0x1000
self.cpu.x_index = 0x00
self.cpu.LDA(self.cpu.indirect_x_mode())
self.assertEqual(self.cpu.accumulator, 0x05)
self.cpu.y_index = 0x00
self.cpu.LDA(self.cpu.indirect_y_mode())
self.assertEqual(self.cpu.accumulator, 0x05)
self.cpu.y_index = 0x00
self.cpu.LDA(self.cpu.indirect_y_mode())
self.assertEqual(self.cpu.accumulator, 0x05)
self.cpu.x_index = 0x00
self.cpu.LDA(self.cpu.indirect_x_mode())
self.assertEqual(self.cpu.accumulator, 0x05)
self.cpu.x_index = 0xFF
self.cpu.LDA(self.cpu.indirect_x_mode())
self.assertEqual(self.cpu.accumulator, 0x05)
self.assertEqual(self.cpu.indirect_mode(), 0xF000)
class TestStackOperations(unittest.TestCase):
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
def test_TSX(self):
s = self.cpu.stack_pointer
self.cpu.TSX()
self.assertEqual(self.cpu.x_index, s)
# @@@ check NZ?
def test_TXS(self):
x = self.cpu.x_index
self.cpu.TXS()
self.assertEqual(self.cpu.stack_pointer, x)
def test_PHA_and_PLA(self):
self.cpu.accumulator = 0x00
self.cpu.PHA()
self.cpu.accumulator = 0x01
self.cpu.PHA()
self.cpu.accumulator = 0xFF
self.cpu.PHA()
self.assertEqual(self.cpu.accumulator, 0xFF)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.sign_flag, 0)
self.cpu.PLA()
self.assertEqual(self.cpu.accumulator, 0xFF)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.sign_flag, 1)
self.cpu.PLA()
self.assertEqual(self.cpu.accumulator, 0x01)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.sign_flag, 0)
self.cpu.PLA()
self.assertEqual(self.cpu.accumulator, 0x00)
self.assertEqual(self.cpu.zero_flag, 1)
self.assertEqual(self.cpu.sign_flag, 0)
def test_PHP_and_PLP(self):
p = self.cpu.status_as_byte()
self.cpu.PHP()
self.cpu.status_from_byte(0xFF)
self.cpu.PLP()
self.assertEqual(self.cpu.status_as_byte(), p)
class TestShiftOperations(unittest.TestCase):
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
def test_ASL(self):
self.cpu.accumulator = 0x01
self.cpu.ASL()
self.assertEqual(self.cpu.accumulator, 0x02)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.carry_flag, 0)
self.memory.write_byte(None, 0x1000, 0x02)
self.cpu.ASL(0x1000)
self.assertEqual(self.memory.read_byte(None, 0x1000), 0x04)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.carry_flag, 0)
self.cpu.accumulator = 0x80
self.cpu.ASL()
self.assertEqual(self.cpu.accumulator, 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.assertEqual(self.cpu.carry_flag, 1)
def test_LSR(self):
self.cpu.accumulator = 0x01
self.cpu.LSR()
self.assertEqual(self.cpu.accumulator, 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.assertEqual(self.cpu.carry_flag, 1)
self.memory.write_byte(None, 0x1000, 0x01)
self.cpu.LSR(0x1000)
self.assertEqual(self.memory.read_byte(None, 0x1000), 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.assertEqual(self.cpu.carry_flag, 1)
self.cpu.accumulator = 0x80
self.cpu.LSR()
self.assertEqual(self.cpu.accumulator, 0x40)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.carry_flag, 0)
def test_ROL(self):
self.cpu.carry_flag = 0
self.cpu.accumulator = 0x80
self.cpu.ROL()
self.assertEqual(self.cpu.accumulator, 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.assertEqual(self.cpu.carry_flag, 1)
self.cpu.carry_flag = 1
self.cpu.accumulator = 0x80
self.cpu.ROL()
self.assertEqual(self.cpu.accumulator, 0x01)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0) # @@@
self.assertEqual(self.cpu.carry_flag, 1)
self.cpu.carry_flag = 0
self.memory.write_byte(None, 0x1000, 0x80)
self.cpu.ROL(0x1000)
self.assertEqual(self.memory.read_byte(None, 0x1000), 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1) # @@@
self.assertEqual(self.cpu.carry_flag, 1)
self.cpu.carry_flag = 1
self.memory.write_byte(None, 0x1000, 0x80)
self.cpu.ROL(0x1000)
self.assertEqual(self.memory.read_byte(None, 0x1000), 0x01)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0) # @@@
self.assertEqual(self.cpu.carry_flag, 1)
def test_ROR(self):
self.cpu.carry_flag = 0
self.cpu.accumulator = 0x01
self.cpu.ROR()
self.assertEqual(self.cpu.accumulator, 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1) # @@@
self.assertEqual(self.cpu.carry_flag, 1)
self.cpu.carry_flag = 1
self.cpu.accumulator = 0x01
self.cpu.ROR()
self.assertEqual(self.cpu.accumulator, 0x80)
self.assertEqual(self.cpu.sign_flag, 1) # @@@
self.assertEqual(self.cpu.zero_flag, 0) # @@@
self.assertEqual(self.cpu.carry_flag, 1)
self.cpu.carry_flag = 0
self.memory.write_byte(None, 0x1000, 0x01)
self.cpu.ROR(0x1000)
self.assertEqual(self.memory.read_byte(None, 0x1000), 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1) # @@@
self.assertEqual(self.cpu.carry_flag, 1)
self.cpu.carry_flag = 1
self.memory.write_byte(None, 0x1000, 0x01)
self.cpu.ROR(0x1000)
self.assertEqual(self.memory.read_byte(None, 0x1000), 0x80)
self.assertEqual(self.cpu.sign_flag, 1) # @@@
self.assertEqual(self.cpu.zero_flag, 0) # @@@
self.assertEqual(self.cpu.carry_flag, 1)
class TestIncrementDecrementOperations(unittest.TestCase):
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
def test_INC(self):
self.memory.write_byte(None, 0x1000, 0x00)
self.cpu.INC(0x1000)
self.assertEqual(self.memory.read_byte(None, 0x1000), 0x01)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.memory.write_byte(None, 0x1000, 0x7F)
self.cpu.INC(0x1000)
self.assertEqual(self.memory.read_byte(None, 0x1000), 0x80)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
self.memory.write_byte(None, 0x1000, 0xFF)
self.cpu.INC(0x1000)
self.assertEqual(self.memory.read_byte(None, 0x1000), 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
def test_INX(self):
self.cpu.x_index = 0x00
self.cpu.INX()
self.assertEqual(self.cpu.x_index, 0x01)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.x_index = 0x7F
self.cpu.INX()
self.assertEqual(self.cpu.x_index, 0x80)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.x_index = 0xFF
self.cpu.INX()
self.assertEqual(self.cpu.x_index, 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
def test_INY(self):
self.cpu.y_index = 0x00
self.cpu.INY()
self.assertEqual(self.cpu.y_index, 0x01)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.y_index = 0x7F
self.cpu.INY()
self.assertEqual(self.cpu.y_index, 0x80)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.y_index = 0xFF
self.cpu.INY()
self.assertEqual(self.cpu.y_index, 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
def test_DEC(self):
self.memory.write_byte(None, 0x1000, 0x01)
self.cpu.DEC(0x1000)
self.assertEqual(self.memory.read_byte(None, 0x1000), 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.memory.write_byte(None, 0x1000, 0x80)
self.cpu.DEC(0x1000)
self.assertEqual(self.memory.read_byte(None, 0x1000), 0x7F)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.memory.write_byte(None, 0x1000, 0x00)
self.cpu.DEC(0x1000)
self.assertEqual(self.memory.read_byte(None, 0x1000), 0xFF)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
def test_DEX(self):
self.cpu.x_index = 0x01
self.cpu.DEX()
self.assertEqual(self.cpu.x_index, 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.cpu.x_index = 0x80
self.cpu.DEX()
self.assertEqual(self.cpu.x_index, 0x7F)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.x_index = 0x00
self.cpu.DEX()
self.assertEqual(self.cpu.x_index, 0xFF)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
def test_DEY(self):
self.cpu.y_index = 0x01
self.cpu.DEY()
self.assertEqual(self.cpu.y_index, 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.cpu.y_index = 0x80
self.cpu.DEY()
self.assertEqual(self.cpu.y_index, 0x7F)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.y_index = 0x00
self.cpu.DEY()
self.assertEqual(self.cpu.y_index, 0xFF)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
class TestArithmeticOperations(unittest.TestCase):
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
def test_ADC_without_BCD(self):
## test cases from http://www.6502.org/tutorials/vflag.html
# 1 + 1 = 2 (C = 0; V = 0)
self.cpu.carry_flag = 0
self.cpu.accumulator = 0x01
self.memory.write_byte(None, 0x1000, 0x01)
self.cpu.ADC(0x1000)
self.assertEqual(self.cpu.accumulator, 0x02)
self.assertEqual(self.cpu.carry_flag, 0)
self.assertEqual(self.cpu.overflow_flag, 0)
# 1 + -1 = 0 (C = 1; V = 0)
self.cpu.carry_flag = 0
self.cpu.accumulator = 0x01
self.memory.write_byte(None, 0x1000, 0xFF)
self.cpu.ADC(0x1000)
self.assertEqual(self.cpu.accumulator, 0x00)
self.assertEqual(self.cpu.carry_flag, 1)
self.assertEqual(self.cpu.overflow_flag, 0)
# 127 + 1 = 128 (C = 0; V = 1)
self.cpu.carry_flag = 0
self.cpu.accumulator = 0x7F
self.memory.write_byte(None, 0x1000, 0x01)
self.cpu.ADC(0x1000)
self.assertEqual(self.cpu.accumulator, 0x80) # @@@
self.assertEqual(self.cpu.carry_flag, 0)
self.assertEqual(self.cpu.overflow_flag, 1)
# -128 + -1 = -129 (C = 1; V = 1)
self.cpu.carry_flag = 0
self.cpu.accumulator = 0x80
self.memory.write_byte(None, 0x1000, 0xFF)
self.cpu.ADC(0x1000)
self.assertEqual(self.cpu.accumulator, 0x7F) # @@@
self.assertEqual(self.cpu.carry_flag, 1)
self.assertEqual(self.cpu.overflow_flag, 1)
# 63 + 64 + 1 = 128 (C = 0; V = 1)
self.cpu.carry_flag = 1
self.cpu.accumulator = 0x3F
self.memory.write_byte(None, 0x1000, 0x40)
self.cpu.ADC(0x1000)
self.assertEqual(self.cpu.accumulator, 0x80)
self.assertEqual(self.cpu.carry_flag, 0)
self.assertEqual(self.cpu.overflow_flag, 1)
def test_SBC_without_BCD(self):
self.cpu.accumulator = 0x02
self.memory.write_byte(None, 0x1000, 0x01)
self.cpu.SBC(0x1000)
self.assertEqual(self.cpu.accumulator, 0x00)
self.assertEqual(self.cpu.carry_flag, 1)
self.assertEqual(self.cpu.overflow_flag, 0)
self.cpu.accumulator = 0x01
self.memory.write_byte(None, 0x1000, 0x02)
self.cpu.SBC(0x1000)
self.assertEqual(self.cpu.accumulator, 0xFF)
self.assertEqual(self.cpu.carry_flag, 0)
self.assertEqual(self.cpu.overflow_flag, 0) # @@@
## test cases from http://www.6502.org/tutorials/vflag.html
# 0 - 1 = -1 (V = 0)
self.cpu.carry_flag = 1
self.cpu.accumulator = 0x00
self.memory.write_byte(None, 0x1000, 0x01)
self.cpu.SBC(0x1000)
self.assertEqual(self.cpu.accumulator, 0xFF)
self.assertEqual(self.cpu.carry_flag, 0)
self.assertEqual(self.cpu.overflow_flag, 0) # @@@
# -128 - 1 = -129 (V = 1)
self.cpu.carry_flag = 1
self.cpu.accumulator = 0x80
self.memory.write_byte(None, 0x1000, 0x01)
self.cpu.SBC(0x1000)
self.assertEqual(self.cpu.accumulator, 0x7F)
self.assertEqual(self.cpu.carry_flag, 1)
self.assertEqual(self.cpu.overflow_flag, 1)
# 127 - -1 = 128 (V = 1)
self.cpu.carry_flag = 1
self.cpu.accumulator = 0x7F
self.memory.write_byte(None, 0x1000, 0xFF)
self.cpu.SBC(0x1000)
self.assertEqual(self.cpu.accumulator, 0x80)
self.assertEqual(self.cpu.carry_flag, 0)
self.assertEqual(self.cpu.overflow_flag, 1)
# -64 -64 -1 = -129 (V = 1)
self.cpu.carry_flag = 0
self.cpu.accumulator = 0xC0
self.memory.write_byte(None, 0x1000, 0x40)
self.cpu.SBC(0x1000)
self.assertEqual(self.cpu.accumulator, 0x7F)
self.assertEqual(self.cpu.carry_flag, 1)
self.assertEqual(self.cpu.overflow_flag, 1) # @@@
## @@@ BCD versions still to do
def test_CMP(self):
self.cpu.accumulator = 0x0A
self.memory.write_byte(None, 0x1000, 0x09)
self.cpu.CMP(0x1000)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.carry_flag, 1)
self.cpu.accumulator = 0x0A
self.memory.write_byte(None, 0x1000, 0x0B)
self.cpu.CMP(0x1000)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.carry_flag, 0)
self.cpu.accumulator = 0x0A
self.memory.write_byte(None, 0x1000, 0x0A)
self.cpu.CMP(0x1000)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.assertEqual(self.cpu.carry_flag, 1)
self.cpu.accumulator = 0xA0
self.memory.write_byte(None, 0x1000, 0x0A)
self.cpu.CMP(0x1000)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.carry_flag, 1)
self.cpu.accumulator = 0x0A
self.memory.write_byte(None, 0x1000, 0xA0)
self.cpu.CMP(0x1000)
self.assertEqual(self.cpu.sign_flag, 0) # @@@
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.carry_flag, 0)
def test_CPX(self):
self.cpu.x_index = 0x0A
self.memory.write_byte(None, 0x1000, 0x09)
self.cpu.CPX(0x1000)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.carry_flag, 1)
self.cpu.x_index = 0x0A
self.memory.write_byte(None, 0x1000, 0x0B)
self.cpu.CPX(0x1000)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.carry_flag, 0)
self.cpu.x_index = 0x0A
self.memory.write_byte(None, 0x1000, 0x0A)
self.cpu.CPX(0x1000)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.assertEqual(self.cpu.carry_flag, 1)
self.cpu.x_index = 0xA0
self.memory.write_byte(None, 0x1000, 0x0A)
self.cpu.CPX(0x1000)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.carry_flag, 1)
self.cpu.x_index = 0x0A
self.memory.write_byte(None, 0x1000, 0xA0)
self.cpu.CPX(0x1000)
self.assertEqual(self.cpu.sign_flag, 0) # @@@
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.carry_flag, 0)
def test_CPY(self):
self.cpu.y_index = 0x0A
self.memory.write_byte(None, 0x1000, 0x09)
self.cpu.CPY(0x1000)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.carry_flag, 1)
self.cpu.y_index = 0x0A
self.memory.write_byte(None, 0x1000, 0x0B)
self.cpu.CPY(0x1000)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.carry_flag, 0)
self.cpu.y_index = 0x0A
self.memory.write_byte(None, 0x1000, 0x0A)
self.cpu.CPY(0x1000)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.assertEqual(self.cpu.carry_flag, 1)
self.cpu.y_index = 0xA0
self.memory.write_byte(None, 0x1000, 0x0A)
self.cpu.CPY(0x1000)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.carry_flag, 1)
self.cpu.y_index = 0x0A
self.memory.write_byte(None, 0x1000, 0xA0)
self.cpu.CPY(0x1000)
self.assertEqual(self.cpu.sign_flag, 0) # @@@
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.carry_flag, 0)
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
self.memory.load(0x1000, [0x00, 0x01, 0x7F, 0x80, 0xFF])
class TestLogicalOperations(unittest.TestCase):
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
def test_AND(self):
self.memory.write_byte(None, 0x1000, 0x37)
self.cpu.accumulator = 0x34
self.cpu.AND(0x1000)
self.assertEqual(self.cpu.accumulator, 0x34)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.sign_flag, 0)
self.cpu.accumulator = 0x40
self.cpu.AND(0x1000)
self.assertEqual(self.cpu.accumulator, 0x00)
self.assertEqual(self.cpu.zero_flag, 1)
self.assertEqual(self.cpu.sign_flag, 0)
def test_EOR(self):
self.memory.write_byte(None, 0x1000, 0x37)
self.cpu.accumulator = 0x34
self.cpu.EOR(0x1000)
self.assertEqual(self.cpu.accumulator, 0x03)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.sign_flag, 0)
self.cpu.accumulator = 0x90
self.cpu.EOR(0x1000)
self.assertEqual(self.cpu.accumulator, 0xA7)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.sign_flag, 1)
self.cpu.accumulator = 0x37
self.cpu.EOR(0x1000)
self.assertEqual(self.cpu.accumulator, 0x00)
self.assertEqual(self.cpu.zero_flag, 1)
self.assertEqual(self.cpu.sign_flag, 0)
def test_ORA(self):
self.memory.write_byte(None, 0x1000, 0x37)
self.cpu.accumulator = 0x34
self.cpu.ORA(0x1000)
self.assertEqual(self.cpu.accumulator, 0x37)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.sign_flag, 0)
self.cpu.accumulator = 0x90
self.cpu.ORA(0x1000)
self.assertEqual(self.cpu.accumulator, 0xB7)
self.assertEqual(self.cpu.zero_flag, 0)
self.assertEqual(self.cpu.sign_flag, 1)
self.cpu.accumulator = 0x00
self.cpu.ORA(0x1001)
self.assertEqual(self.cpu.accumulator, 0x00)
self.assertEqual(self.cpu.zero_flag, 1)
self.assertEqual(self.cpu.sign_flag, 0)
def test_BIT(self):
self.memory.write_byte(None, 0x1000, 0x00)
self.cpu.accumulator = 0x00
self.cpu.BIT(0x1000)
self.assertEqual(self.cpu.overflow_flag, 0)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.memory.write_byte(None, 0x1000, 0x40)
self.cpu.accumulator = 0x00
self.cpu.BIT(0x1000)
self.assertEqual(self.cpu.overflow_flag, 1)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.memory.write_byte(None, 0x1000, 0x80)
self.cpu.accumulator = 0x00
self.cpu.BIT(0x1000)
self.assertEqual(self.cpu.overflow_flag, 0)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 1)
self.memory.write_byte(None, 0x1000, 0xC0)
self.cpu.accumulator = 0x00
self.cpu.BIT(0x1000)
self.assertEqual(self.cpu.overflow_flag, 1)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 1)
self.memory.write_byte(None, 0x1000, 0xC0)
self.cpu.accumulator = 0xC0
self.cpu.BIT(0x1000)
self.assertEqual(self.cpu.overflow_flag, 1)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
class TestLoadStoreOperations(unittest.TestCase):
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
self.memory.load(0x1000, [0x00, 0x01, 0x7F, 0x80, 0xFF])
def test_LDA(self):
self.cpu.LDA(0x1000)
self.assertEqual(self.cpu.accumulator, 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.cpu.LDA(0x1001)
self.assertEqual(self.cpu.accumulator, 0x01)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.LDA(0x1002)
self.assertEqual(self.cpu.accumulator, 0x7F)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.LDA(0x1003)
self.assertEqual(self.cpu.accumulator, 0x80)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.LDA(0x1004)
self.assertEqual(self.cpu.accumulator, 0xFF)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
def test_LDX(self):
self.cpu.LDX(0x1000)
self.assertEqual(self.cpu.x_index, 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.cpu.LDX(0x1001)
self.assertEqual(self.cpu.x_index, 0x01)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.LDX(0x1002)
self.assertEqual(self.cpu.x_index, 0x7F)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.LDX(0x1003)
self.assertEqual(self.cpu.x_index, 0x80)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.LDX(0x1004)
self.assertEqual(self.cpu.x_index, 0xFF)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
def test_LDY(self):
self.cpu.LDY(0x1000)
self.assertEqual(self.cpu.y_index, 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.cpu.LDY(0x1001)
self.assertEqual(self.cpu.y_index, 0x01)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.LDY(0x1002)
self.assertEqual(self.cpu.y_index, 0x7F)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.LDY(0x1003)
self.assertEqual(self.cpu.y_index, 0x80)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.LDY(0x1004)
self.assertEqual(self.cpu.y_index, 0xFF)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
def test_STA(self):
self.cpu.accumulator = 0x37
self.cpu.STA(0x2000)
self.assertEqual(self.memory.read_byte(None, 0x2000), 0x37)
def test_STX(self):
self.cpu.x_index = 0x38
self.cpu.STX(0x2000)
self.assertEqual(self.memory.read_byte(None, 0x2000), 0x38)
def test_STY(self):
self.cpu.y_index = 0x39
self.cpu.STY(0x2000)
self.assertEqual(self.memory.read_byte(None, 0x2000), 0x39)
class TestBranchOperations(unittest.TestCase):
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
def test_BCC(self):
self.cpu.program_counter = 0x1000
self.cpu.carry_flag = 1
self.cpu.BCC(0x2000)
self.assertEqual(self.cpu.program_counter, 0x1000)
self.cpu.program_counter = 0x1000
self.cpu.carry_flag = 0
self.cpu.BCC(0x2000)
self.assertEqual(self.cpu.program_counter, 0x2000)
def test_BCS(self):
self.cpu.program_counter = 0x1000
self.cpu.carry_flag = 0
self.cpu.BCS(0x2000)
self.assertEqual(self.cpu.program_counter, 0x1000)
self.cpu.program_counter = 0x1000
self.cpu.carry_flag = 1
self.cpu.BCS(0x2000)
self.assertEqual(self.cpu.program_counter, 0x2000)
def test_BEQ(self):
self.cpu.program_counter = 0x1000
self.cpu.zero_flag = 0
self.cpu.BEQ(0x2000)
self.assertEqual(self.cpu.program_counter, 0x1000)
self.cpu.program_counter = 0x1000
self.cpu.zero_flag = 1
self.cpu.BEQ(0x2000)
self.assertEqual(self.cpu.program_counter, 0x2000)
def test_BMI(self):
self.cpu.program_counter = 0x1000
self.cpu.sign_flag = 0
self.cpu.BMI(0x2000)
self.assertEqual(self.cpu.program_counter, 0x1000)
self.cpu.program_counter = 0x1000
self.cpu.sign_flag = 1
self.cpu.BMI(0x2000)
self.assertEqual(self.cpu.program_counter, 0x2000)
def test_BNE(self):
self.cpu.program_counter = 0x1000
self.cpu.zero_flag = 1
self.cpu.BNE(0x2000)
self.assertEqual(self.cpu.program_counter, 0x1000)
self.cpu.program_counter = 0x1000
self.cpu.zero_flag = 0
self.cpu.BNE(0x2000)
self.assertEqual(self.cpu.program_counter, 0x2000)
def test_BPL(self):
self.cpu.program_counter = 0x1000
self.cpu.sign_flag = 1
self.cpu.BPL(0x2000)
self.assertEqual(self.cpu.program_counter, 0x1000)
self.cpu.program_counter = 0x1000
self.cpu.sign_flag = 0
self.cpu.BPL(0x2000)
self.assertEqual(self.cpu.program_counter, 0x2000)
def test_BVC(self):
self.cpu.program_counter = 0x1000
self.cpu.overflow_flag = 1
self.cpu.BVC(0x2000)
self.assertEqual(self.cpu.program_counter, 0x1000)
self.cpu.program_counter = 0x1000
self.cpu.overflow_flag = 0
self.cpu.BVC(0x2000)
self.assertEqual(self.cpu.program_counter, 0x2000)
def test_BVS(self):
self.cpu.program_counter = 0x1000
self.cpu.overflow_flag = 0
self.cpu.BVS(0x2000)
self.assertEqual(self.cpu.program_counter, 0x1000)
self.cpu.program_counter = 0x1000
self.cpu.overflow_flag = 1
self.cpu.BVS(0x2000)
self.assertEqual(self.cpu.program_counter, 0x2000)
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
class TestRegisterTransferOperations(unittest.TestCase):
def setUp(self):
self.memory = Memory(use_bus=False)
self.cpu = CPU(self.memory)
def test_TAX(self):
self.cpu.accumulator = 0x00
self.cpu.TAX()
self.assertEqual(self.cpu.x_index, 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.cpu.accumulator = 0x01
self.cpu.TAX()
self.assertEqual(self.cpu.x_index, 0x01)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.accumulator = 0xFF
self.cpu.TAX()
self.assertEqual(self.cpu.x_index, 0xFF)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
def test_TAY(self):
self.cpu.accumulator = 0x00
self.cpu.TAY()
self.assertEqual(self.cpu.y_index, 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.cpu.accumulator = 0x01
self.cpu.TAY()
self.assertEqual(self.cpu.y_index, 0x01)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.accumulator = 0xFF
self.cpu.TAY()
self.assertEqual(self.cpu.y_index, 0xFF)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
def test_TXA(self):
self.cpu.x_index = 0x00
self.cpu.TXA()
self.assertEqual(self.cpu.accumulator, 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.cpu.x_index = 0x01
self.cpu.TXA()
self.assertEqual(self.cpu.accumulator, 0x01)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.x_index = 0xFF
self.cpu.TXA()
self.assertEqual(self.cpu.accumulator, 0xFF)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
def test_TYA(self):
self.cpu.y_index = 0x00
self.cpu.TYA()
self.assertEqual(self.cpu.accumulator, 0x00)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 1)
self.cpu.y_index = 0x01
self.cpu.TYA()
self.assertEqual(self.cpu.accumulator, 0x01)
self.assertEqual(self.cpu.sign_flag, 0)
self.assertEqual(self.cpu.zero_flag, 0)
self.cpu.y_index = 0xFF
self.cpu.TYA()
self.assertEqual(self.cpu.accumulator, 0xFF)
self.assertEqual(self.cpu.sign_flag, 1)
self.assertEqual(self.cpu.zero_flag, 0)
