Hackers, Heroes of the Computer Revolution - Steven Levy (top books to read txt) 📗

dropped out Hacking the M-Boards, for under its locks are the switches, and under its control the advance around the layout, Hacking!

Hacking the grungy, hairy, sprawling hacks of youth; uncabled, frying diodes, proud to be Switch-thrower, Fuze-tester, Maker of Routes, Player with Railroads, and Advance Chopper to the System.

 

Whenever they could, Samson and the others would slip off to the EAM room with their plug boards, trying to use the machine to keep track of the switches underneath the layout. Just as important, they were seeing what the electromechanical counter could do, taking it to its limit.

 

That spring of 1959, a new course was offered at MIT. It was the first course in programming a computer that freshmen could take.

The teacher was a distant man with a wild shock of hair and an equally unruly beard—John McCarthy. A master mathematician, McCarthy was a classically absent-minded professor; stories abounded about his habit of suddenly answering a question hours, sometimes even days after it was first posed to him. He would approach you in the hallway, and with no salutation would begin speaking in his robotically precise diction, as if the pause in conversation had been only a fraction of a second, and not a week. Most likely, his belated response would be brilliant.

 

McCarthy was one of a very few people working in an entirely new form of scientific inquiry with computers. The volatile and controversial nature of his field of study was obvious from the very arrogance of the name that McCarthy had bestowed upon it: Artificial Intelligence. This man actually thought that computers could be SMART. Even at such a science-intensive place as MIT, most people considered the thought ridiculous: they considered computers to be useful, if somewhat absurdly expensive, tools for number-crunching huge calculations and for devising missile defense systems (as MIT’s largest computer, the Whirlwind, had done for the early-warning SAGE system), but scoffed at the thought that computers themselves could actually be a scientific field of study, Computer Science did not officially exist at MIT in the late fifties, and McCarthy and his fellow computer specialists worked in the Electrical Engineering Department, which offered the course, No. 641, that Kotok, Samson, and a few other TRMC members took that spring.

 

McCarthy had started a mammoth program on the IBM 704—the Hulking Giant—that would give it the extraordinary ability to play chess. To critics of the budding field of Artificial Intelligence, this was just one example of the boneheaded optimism of people like John McCarthy. But McCarthy had a certain vision of what computers could do, and playing chess was only the beginning.

 

All fascinating stuff, but not the vision that was driving Kotok and Samson and the others. They wanted to learn how to WORK the damn machines, and while this new programming language called LISP that McCarthy was talking about in 641 was interesting, it was not nearly as interesting as the act of programming, or that fantastic moment when you got your printout back from the Priesthood—word from the source itself!—and could then spend hours poring over the results of the program, what had gone wrong with it, how it could be improved. The TMRC hackers were devising ways to get into closer contact with the IBM 704, which soon was upgraded to a newer model called the 709. By hanging out at the computation center in the wee hours of the morning, and by getting to know the Priesthood, and by bowing and scraping the requisite number of times, people like Kotok were eventually allowed to push a few buttons on the machine, and watch the lights as it worked.

 

There were secrets to those IBM machines that had been painstakingly learned by some of the older people at MIT with access to the 704 and friends among the Priesthood. Amazingly, a few of these programmers, grad students working with McCarthy, had even written a program that utilized one of the rows of tiny lights: the lights would be lit in such an order that it looked like a little ball was being passed from right to left: if an operator hit a switch at just the right time, the motion of the lights could be reversed—Computer Ping-Pong! This obviously was the kind of thing that you’d show off to impress your peers, who would then take a look at the actual program you had written and see how it was done.

 

To top the program, someone else might try to do the same thing with fewer instructions—a worthy endeavor, since there was so little room in the small “memory” of the computers of those days that not many instructions could fit into them, John McCarthy had once noticed how his graduate students who loitered around the 704 would work over their computer programs to get the most out of the fewest instructions, and get the program compressed so that fewer cards would need to be fed to the machine. Shaving off an instruction or two was almost an obsession with them.

McCarthy compared these students to ski bums. They got the same kind of primal thrill from “maximizing code” as fanatic skiers got from swooshing frantically down a hill. So the practice of taking a computer program and trying to cut off instructions without affecting the outcome came to be called “program bumming,” and you would often hear people mumbling things like “Maybe I can bum a few instructions out and get the octal correction card loader down to three cards instead of four.”

 

McCarthy in 1959 was turning his interest from chess to a new way of talking to the computer, the whole new “language” called LISP.

Alan Kotok and his friends were more than eager to take over the chess project. Working on the batch-processed IBM, they embarked on the gargantuan project of teaching the 704, and later the 709, and even after that its replacement the 7090, how to play the game of kings. Eventually Kotok’s group became the largest users of computer time in the entire MIT computation center.

 

Still, working with the IBM machine was frustrating. There was nothing worse than the long wait between the time you handed in your cards and the time your results were handed back to you. If you had misplaced as much as one letter in one instruction, the program would crash, and you would have to start the whole process over again. It went hand in hand with the stifling proliferation of goddamn RULES that permeated the atmosphere of the computation center. Most of the rules were designed to keep crazy young computer fans like Samson and Kotok and Saunders physically distant from the machine itself. The most rigid rule of all was that no one should be able to actually touch or tamper with the machine itself. This, of course, was what those Signals and Power people were dying to do more than anything else in the world, and the restrictions drove them mad.

 

One priest—a low-level sub-priest, really—on the late-night shift was particularly nasty in enforcing this rule, so Samson devised a suitable revenge. While poking around at Eli’s electronic junk shop one day, he chanced upon an electrical board precisely like the kind of board holding the clunky vacuum tubes which resided inside the IBM. One night, sometime before 4 A.M., this particular sub-priest stepped out for a minute; when he returned, Samson told him that the machine wasn’t working, but they’d found the trouble—and held up the totally smashed module from the old 704 he’d gotten at Eli’s.

 

The sub-priest could hardly get the words out. “W-where did you get that?”

 

Samson, who had wide green eyes that could easily look maniacal, slowly pointed to an open place on the machine rack where, of course, no board had ever been, but the space still looked sadly bare. The sub-priest gasped. He made faces that indicated his bowels were about to give out. He whimpered exhortations to the deity. Visions, no doubt, of a million-dollar deduction from his paycheck began flashing before him. Only after his supervisor, a high priest with some understanding of the mentality of these young wiseguys from the Model Railroad Club, came and explained the situation did he calm down.

 

He was not the last administrator to feel the wrath of a hacker thwarted in the quest for access.

 

*

 

One day a former TMRC member who was now on the MIT faculty paid a visit to the clubroom. His name was Jack Dennis. When he had been an undergraduate in the early 1950s, he had worked furiously underneath the layout. Dennis lately had been working a computer which MIT had just received from Lincoln Lab, a military development laboratory affiliated with the Institute. The computer was called the TX-0, and it was one of the first transistor-run computers in the world. Lincoln Lab had used it specifically to test a giant computer called the TX-2, which had a memory so complex that only with this specially built little brother could its ills be capably diagnosed. Now that its original job was over, the three-million-dollar TX-0 had been shipped over to the Institute on “long-term loan,” and apparently no one at Lincoln Lab had marked a calendar with a return date.

Dennis asked the S&P people at TMRC whether they would like to see it.

 

Hey you nuns! Would you like to meet the Pope?

 

The TX-0 was in Building 26, in the second-floor Radio Laboratory of Electronics (RLE), directly above the first-floor Computation Center which housed the hulking IBM 704. The RLE lab resembled the control room of an antique spaceship. The TX-0, or Tixo, as it was sometimes called, was for its time a midget machine, since it was one of the first computers to use finger-size transistors instead of hand-size vacuum tubes. Still, it took up much of the room, along with its fifteen tons of supporting air-conditioning equipment. The TX-O’s workings were mounted on several tall, thin chassis, like rugged metal bookshelves, with tangled wires and neat little rows of tiny, bottle-like containers in which the transistors were inserted. Another rack had a solid metal front speckled with grim-looking gauges. Facing the racks was an L-shaped console, the control panel of this H. G. Wells spaceship, with a blue countertop for your elbows and papers. On the short arm of the L stood a Flexowriter, which resembled a typewriter converted for tank warfare, its bottom anchored in a military gray housing. Above the top were the control panels, boxlike protrusions painted an institutional yellow. On the sides of the boxes which faced the user were a few gauges, several lines of quarter-inch blinking lights, a matrix of steel toggle switches the size of large grains of rice, and, best of all, an actual cathode ray tube display, round and smoke-gray.

 

The TMRC people were awed. THIS MACHINE DID NOT USE CARDS. The user would first punch in a program onto a long, thin paper tape with a Flexowriter (there were a few extra Flexowriters in an adjoining room), then sit at the console, feed in the program by running the tape through a reader, and be able to sit there while the program ran. If something went wrong with the program, you knew immediately, and you could diagnose the problem by using some of the switches, or checking out which of the lights were blinking or lit. The computer even had an audio output: while the program ran, a speaker underneath the console would make a sort of music, like a poorly tuned electric organ whose notes would vibrate with a fuzzy, ethereal din. The chords on this “organ” would change, depending on what data the machine was reading at any given microsecond; after you were familiar with the tones, you could actually HEAR