Gary and the Astrology Machine
A Story from the Early Days of Personal Computing
The first operating system to qualify as a standard in the developing microcomputer industry was not the result of a carefully planned project involving years of research by dozens of software specialists. Like most of the early significant programs, it originated out of one person’s initiative. And its first commercial application was… unusual.
Gary Kildall was an incurable diagram drawer. When he wanted to make a point while speaking, he would frequently fish around for chalk or a pencil. An academic by profession and inclination, Gary loved teaching but also loved that his new job left him time to program. He was comfortable.
While wrapping up his PhD from the University of Washington, he had moved to Pacific Grove, California to teach at the Naval Postgraduate School. He loved the scenic coastal town; its laid-back, fog-draped ambiance seemed to suit him. Kildall was soft-spoken, possessed of a disarming wit, and was most at ease in a sport shirt and jeans.
The freedom to program was important to him. He had a lot of experience with computers, in both an academic and a practical, hands-on sense. He had been one of two people responsible for keeping the University of Washington’s Burroughs B5500 computer up and running. Later, when the university was acquiring its new CDC 6400 computer, Gary was so well respected for his knowledge of computers that he served as the technical advisor on the purchase.
In mid-1972, Gary Kildall came across an advertisement on a bulletin board that said “MICROCOMPUTER $25.” It sounded like a real bargain to him. He decided to buy one.
It turned out that the $25 price on the Intel 4004 applied only to volume purchasers, and besides, a microprocessor was useless by itself; it needed to be incorporated into a computer. Gary did buy the manual for the Intel 4004, wrote a program on the school’s mainframe to simulate the 4004, and began to write and test 4004 code to determine what he might eventually do with the “bargain basement” 4004 chip.
Gary’s father owned a navigation school in Seattle and had always wanted a machine that could compute navigational triangles. Gary wrote some arithmetic programs to run on the 4004, offhandedly thinking that he might come up with something his father could use. He was just fooling around with the 4004, trying to see how far he could go and with what degree of speed and accuracy. He determined that the processor was pretty limited, but he still loved working with it. Soon thereafter, he traded some 4004 programs to Intel for a development system, a small computer built around the 4004, which was in effect one of the first true microcomputers, albeit not a commercial product.
Intel was impressed by Gary’s work, and when they came out with an 8-bit processor they gave Gary a development system to use in testing software he wrote for the chip. Gary set up the development system in the back of his classroom, in effect creating the Naval Postgraduate School’s first microcomputer lab. Curious students would wander back there after class and tinker with the system for hours. When Intel upgraded the development system from an 8008 processor to an 8080 and supplied Kildall with a display monitor and high-speed paper-tape reader, he and his students had a microcomputer system before anything of the kind existed commercially.
Soon he had the development system working with a disk drive and had written a programming language implementation and an operating system for it. He called his operating system CP/M.
Some of CP/M’s development came about under curious conditions. While he continued teaching, Gary connected with hardware designer Ben Cooper. Cooper suggested they build a machine to chart horoscopes. Gary’s interest was piqued, not because it looked like a good product idea so much as because he wanted to do the math that calculated star positions.
So they built their astrology machine and got it placed in grocery stores, eating quarters like an arcade game and printing out horoscopes. It was a disaster.
The fancy knobs and dials just irritated users and the paper was continually jamming up. “It was a total bust,” Gary later said.
But despite the disappointing results, the astrology machine pushed Gary to fully develop his operating system, which would soon become the default operating system for the nascent personal computer industry.
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