public void TestLDI()
        {
            SignalBus signals = new SignalBus();
            Operation op      = new LDI(null, signals, null);

            signals.Reset();
            op.Step0();
            Assert.IsTrue(signals.MI);
            Assert.IsTrue(signals.CO);

            signals.Reset();
            op.Step1();
            Assert.IsTrue(signals.RO);
            Assert.IsTrue(signals.II);
            Assert.IsTrue(signals.CE);

            signals.Reset();
            op.Step2();
            Assert.IsTrue(signals.IO);
            Assert.IsTrue(signals.AI);
        }