The S-100 bus only outputs +8V, -18V and +18V. The idea is that the board itself will convert this voltage to what the components on the board needs to operate.

The S-100 bus only outputs +8V, -18V and +18V. The idea is that the board itself will convert this voltage to what the components on the board needs to operate. The newly designed board have a newer voltage regulator that outputs 5V and the optional 3.3V from the higher voltage provided by the S-100 bus. You always need to do a voltage conversion on a S-100 card.