diff --git a/asm/ffi.py b/asm/ffi.py
index ccbe40d..3442171 100644
--- a/asm/ffi.py
+++ b/asm/ffi.py
@@ -76,11 +76,26 @@ class CompileError(Exception):
 		self.r = r
 
 class Environment:
-	def getreg(self, reg):
+	def getreg(self, reg, signed=False):
+		""" Get the value at the register.
+
+		:param reg: Register number.
+		:param signed: If the register value should be interpreted
+		as signed.
+		"""
 		if reg >= self.cenv.reglen or reg < 0:
 			raise RegisterOverflowError(r)
-		return creole.from_2c(self.cenv.reg[reg])
+		if signed:
+			return creole.from_2c(self.cenv.reg[reg])
+		else:
+			return self.cenv.reg[reg]
 	def getstk(self, stk):
+		""" Get the value at the stack position.
+
+		:param reg: Register number.
+		:param signed: If the stack value should be interpreted
+		as signed.
+		"""
 		if stk >= self.cenv.stklen or stk < 0:
 			raise StackOverflowError(r)
 		return creole.from_2c(self.cenv.stk[stk])
diff --git a/asm/test.py b/asm/test.py
index 52ae268..f68ff1c 100644
--- a/asm/test.py
+++ b/asm/test.py
@@ -174,7 +174,7 @@ class AddTest(unittest.TestCase):
 		ex = ffi.Environment(p())
 		self.assertEqual(ex(), ffi.RunRet.STOP)
 		self.assertEqual(ex.getreg(0), 30)
-		self.assertEqual(ex.getreg(1), -10)
+		self.assertEqual(ex.getreg(1, signed=True), -10)
 
 	def test_exec_add_throw_imm(self):
 		p = Program()
@@ -217,7 +217,7 @@ class MulTest(unittest.TestCase):
 		p.parse_asm_line("mul r1 r0 -5")
 		ex = ffi.Environment(p())
 		self.assertEqual(ex(), ffi.RunRet.STOP)
-		self.assertEqual(ex.getreg(0), -25)
+		self.assertEqual(ex.getreg(0, signed=True), -25)
 		self.assertEqual(ex.getreg(1), 125)
 
 	def test_exec_mul_throw_imm(self):
@@ -279,7 +279,7 @@ class DivTest(unittest.TestCase):
 		p.parse_asm_line("sdiv r1 r0 -4")
 		ex = ffi.Environment(p())
 		self.assertEqual(ex(), ffi.RunRet.STOP)
-		self.assertEqual(ex.getreg(0), -4)
+		self.assertEqual(ex.getreg(0, signed=True), -4)
 		self.assertEqual(ex.getreg(1), 1)
 
 	def test_exec_div_throw_imm(self):
@@ -351,14 +351,34 @@ class ProgramTest(unittest.TestCase):
 		self.assertEqual(ex.getreg(0), 6)
 		self.assertEqual(ex.getreg(1), 5)
 
-	def test_parse_2_byte_num(self):
-		p = Program()
-		p.parse_asm_line("mov r0 127")
-		p.parse_asm_line("mov r1 128")
-		ex = ffi.Environment(p())
-		self.assertEqual(ex(), ffi.RunRet.STOP)
-		self.assertEqual(ex.getreg(0), 127)
-		self.assertEqual(ex.getreg(1), 128)
+	def range_test(self, st, en, sgn=False):
+		for i in range(st, en):
+			p = Program()
+			p.parse_asm_line(f"mov r0 {i}")
+			ex = ffi.Environment(p())
+			self.assertEqual(ex(), ffi.RunRet.STOP)
+			self.assertEqual(ex.getreg(0, signed=sgn), i)
+
+	def test_parse_imm_compile(self):
+		self.range_test(0, 0x1000)
+		self.range_test(0x1000, 0x1100)
+		self.range_test(0x1FF00, 0x20000)
+		self.range_test(0x20000, 0x20100)
+		self.range_test(0x3FFF00, 0x400000)
+		self.range_test(0x400000, 0x400100)
+		self.range_test(0x7FFFF00, 0x8000000)
+		self.range_test(0x8000000, 0x8000100)
+		self.range_test(0xFFFFFF00, 0x100000000)
+
+	def test_parse_imm_signed(self):
+		self.range_test(0, 0x1000, sgn=True)
+		self.range_test(0x1000, 0x1100, sgn=True)
+		self.range_test(0x1FF00, 0x20000, sgn=True)
+		self.range_test(0x20000, 0x20100, sgn=True)
+		self.range_test(0x3FFF00, 0x400000, sgn=True)
+		self.range_test(0x400000, 0x400100, sgn=True)
+		self.range_test(0x7FFFF00, 0x8000000, sgn=True)
+		self.range_test(-100, 0, sgn=True)
 
 if __name__ == "__main__":
 	unittest.main()