<Several S-100 manufacturers who were still at it in the mid-80's had <regulated +5V on the S-100 backplane. Those who wanted to use their <older S-100 cards in such a machine just jumpered across the 7805's and <viola! More commonplace was the use of constant Voltage transformers or simple preregulation so the +8 really was +8 and not +12 when lightly loaded. Allison