public void RRDTest()
{
PrivateObject z = new PrivateObject(new Z80(new Memory48K()));
Z80_Accessor target = new Z80_Accessor(z);
target.Set16BitRegisters(2, 0x5000);
target.A = 0x84;
target.Memory[0x5000] = 0x20;
target.RRD();
Assert.IsTrue(target.A == 128 && target.Memory[0x5000] == 0x42, "Error: RRD");
}