I used to turn the brightness down to 0 on my mac 512ke when I wasn't using it. That was a physical knob. Since it was convection cooled there wasn't any noise,

I used to turn the brightness down to 0 on my mac 512ke when I wasn't using it. That was a physical knob. Since it was convection cooled there wasn't any noise, and it saved the not inconsiderable time of booting from a double sided floppy.