Return to the Little Kingdom_ Steve Jobs and the Creation of Apple - Michael Moritz [62]
Microprocessors did, however, bring a change of focus. With a computer’s central processing unit reduced to a chip, engineers like Wozniak and Baum felt that some of the broader issues of computer design had evaporated. Instead, they were forced to focus on the best ways of linking the computer on a chip to a board of memory chips, to a television screen or printer, and to a typewriter keyboard. The data sheets accompanying the microprocessors prescribed the rules that bounded the microcomputer designer and left some of the purists feeling hamstrung. Allen Baum complained, “You’re stuck with what you have and you’ve got to make it work right. If something doesn’t work right, you cannot redesign it. It’s a lot less fun.”
If the problems of size had been eliminated, cost was still an issue for threadbare engineers. In 1975 microprocessors like Intel’s 8080 were selling for $179 and Wozniak couldn’t afford them. Baum heard that Hewlett-Packard’s Colorado division was experimenting with the Motorola 6800, a microprocessor introduced about a year after the Intel 8080, which along with a few accessory chips was being offered to employees at a steep discount. Wozniak placed his order while his workmate Myron Tuttle scampered out to buy a technical manual that explained the intricacies of the chip. The choice of microprocessor was the most important decision that a computer hobbyist could make. It became the cause of frustration and exasperation, the source of pleasure and satisfaction, and also shaped the slant of his entire machine. Wozniak’s choice of microprocessor ran counter to fashion in the summer of 1975.
That summer at the Homebrew Club the Intel 8080 formed the center of the universe. The Altair was built around the 8080 and its early popularity spawned a cottage industry of small companies that either made machines that would run programs written for the Altair or made attachments that would plug into the computer. The private peculiarities of microprocessors meant that a program or device designed for one would not work on another. The junction of these peripheral devices for the Altair was known as the S-100 bus because it used one hundred signal lines. Disciples of the 8080 formed religious attachments to the 8080 and S-100 even though they readily admitted that the latter was poorly designed. The people who wrote programs or built peripherals for 8080 computers thought that later, competing microprocessors were doomed. The sheer weight of the programs and the choice of peripherals, so the argument went, would make it more useful to more users and more profitable for more companies. The 8080, they liked to say, had critical mass which was sufficient to consign anything else to oblivion. Lee Felsenstein had plenty of companions who shared his belief that “the 6800 was another world. It wasn’t worth any attention.”
Wozniak bucked the trend and chose the 6800. His interest in the Motorola chip was shaped almost entirely by price but he also thought that it was more like his favorite minicomputers than the 8080. The signals that emerged from the 6800, for example, were synchrononous (and so bore a conceptual resemblance to the architecture of the Data General Nova) while the signals on the 8080 were less predictable. Wozniak started spending his time at Hewlett-Packard delving into the properties of the 6800: finding out how much memory it could cope with, the voltage that it needed, the speed with which it executed instructions, and the pattern of its signals. On paper he plotted out a design of a computer built around the 6800. The design was an enhancement of the prototype he had built for Computer Conversor. “I designed it just for fun. I could do a whole bunch of things I’d wanted to do five years before and didn’t have the money to do.”
The economics of the semiconductor industry were also in Wozniak’s favor. Chips seldom sold long at their introductory price. Competing devices from the