1 instruction; 1 instruction of 16 bits—6 ones and zeros. A couple of those ones
and zeros told it which of four registers to put on one side of the arithmetic
unit. A couple more bits told it which other of the four registers to use. Another
couple of bits told it whether to shift or rotate the result after it finished, left or
right, which is equivalent to multiplying or dividing by 2. There were bits as to
whether you should set a carry (just like you learned addition in elementary
school, you have carries—well, computer circuits worked the same way). By the
time you were done, all of these 16 bits had certain meanings. I looked at it
when I went to design a Nova, and it turned out that two of the bits selected
one of the four registers, so I ran them to a four-way multiplexer chip and it just
flowed in. It’s like those two bits fit a chip. I didn’t have to make up a bunch of
logic that decides “do this and this and this, and gate those over here, and put a
Steve Wozniak 35
signal down there.” I didn’t have to do all that stuff. It just flowed logically.
Three of the bits flowed down to a logic chip to tell it whether to add, or, or
exclusive-or. Another bit just got fed in as the carry into the adder. By the time
I was done, the design of the Nova was half as many chips as all of the other
minicomputers from Varian, Digital Equipment Corp., Hewlett-Packard—all
of the minicomputers of the time (I was designing them all). And I saw that
Nova was half as many chips and just as good a computer. What was different?
The architecture was really an architecture that just fit right to the very fewest
chips.
My whole life was basically trying to optimize things. You don’t just save
parts, but every time you save parts you save on complexity and reliability, the
amount of time it takes to understand something. And how good you can build
it without errors and bugs and flaws.
Livingston: You were designing all of these different types of computers during
high school at home, for fun?
Wozniak: Yes, because I could never build one. Not only that, but I would
design one and design it over and over and over—each one of the computers—
because new chips would come out. I would take the new chips and redesign
some computer I’d done before because I’d come up with a clever idea about
how I could save two more chips. “I’ll do it in 42 chips instead of 44 chips.”
The reason I did that was because I had no money. I could never build one.
Chips back then were . . . like I said, to buy a computer built, it was like a down

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