That latter trick was used on many an early micro that was designed for TV use. Back then games had a very intimate relationship with the CPU and the electron b

That latter trick was used on many an early micro that was designed for TV use. Back then games had a very intimate relationship with the CPU and the electron beam of the TV. For example using the cycles while the beam was moving from the bottom right to the top left to start a new image to do non-graphical work.