Not just ALUs, but full blown processors with things like branch prediction. The last that got a good deal of attention was Sammyuri's "Chungus 2", from December last year.
It runs at 1 Hz though, about 1000 times slower than an Atari 2600.
1 Hz is unironically an amazing achievement in minecraft. 20 Hz is the theoretical maximum without abusing bugs, and higher values are technically possible through 0-tick pulsing but most likely so utterly devastating to design that you'd have to be the worst kind of masochist to start trying.
