Part 46

But there's more. JEDGAR would ask the user for `license to kill'. If the user said yes, then JEDGAR would actually {gun} the job of the {luser} who was spying. Unfortunately, people found that this made life too violent, especially when tourists learned about it. One of the systems hackers solved the problem by replacing JEDGAR with another program that only pretended to do its job. It took a long time to do this, because every copy of JEDGAR had to be patched. To this day no one knows how many people never figured out that JEDGAR had been defanged.

:The Story of Mel, a Real Programmer: =====================================

This was posted to USENET by its author, Ed Nather (utastro!nather), on May 21, 1983.

A recent article devoted to the *macho* side of programming made the bald and unvarnished statement:

Real Programmers write in FORTRAN.

Maybe they do now, in this decadent era of Lite beer, hand calculators, and "user-friendly" software but back in the Good Old Days, when the term "software" sounded funny and Real Computers were made out of drums and vacuum tubes, Real Programmers wrote in machine code. Not FORTRAN. Not RATFOR. Not, even, assembly language. Machine Code. Raw, unadorned, inscrutable hexadecimal numbers. Directly.

Lest a whole new generation of programmers grow up in ignorance of this glorious past, I feel duty-bound to describe, as best I can through the generation gap, how a Real Programmer wrote code. I'll call him Mel, because that was his name.

I first met Mel when I went to work for Royal McBee Computer Corp., a now-defunct subsidiary of the typewriter company. The firm manufactured the LGP-30, a small, cheap (by the standards of the day) drum-memory computer, and had just started to manufacture the RPC-4000, a much-improved, bigger, better, faster --- drum-memory computer. Cores cost too much, and weren't here to stay, anyway. (That's why you haven't heard of the company, or the computer.)

I had been hired to write a FORTRAN compiler for this new marvel and Mel was my guide to its wonders. Mel didn't approve of compilers.

"If a program can't rewrite its own code", he asked, "what good is it?"

Mel had written, in hexadecimal, the most popular computer program the company owned. It ran on the LGP-30 and played blackjack with potential customers at computer shows. Its effect was always dramatic. The LGP-30 booth was packed at every show, and the IBM salesmen stood around talking to each other. Whether or not this actually sold computers was a question we never discussed.

Mel's job was to re-write the blackjack program for the RPC-4000. (Port? What does that mean?) The new computer had a one-plus-one addressing scheme, in which each machine instruction, in addition to the operation code and the address of the needed operand, had a second address that indicated where, on the revolving drum, the next instruction was located.

In modern parlance, every single instruction was followed by a GO TO! Put *that* in Pascal's pipe and smoke it.

Mel loved the RPC-4000 because he could optimize his code: that is, locate instructions on the drum so that just as one finished its job, the next would be just arriving at the "read head" and available for immediate execution. There was a program to do that job, an "optimizing assembler", but Mel refused to use it.

"You never know where it's going to put things", he explained, "so you'd have to use separate constants".

It was a long time before I understood that remark. Since Mel knew the numerical value of every operation code, and assigned his own drum addresses, every instruction he wrote could also be considered a numerical constant. He could pick up an earlier "add" instruction, say, and multiply by it, if it had the right numeric value. His code was not easy for someone else to modify.

I compared Mel's hand-optimized programs with the same code massaged by the optimizing assembler program, and Mel's always ran faster. That was because the "top-down" method of program design hadn't been invented yet, and Mel wouldn't have used it anyway. He wrote the innermost parts of his program loops first, so they would get first choice of the optimum address locations on the drum. The optimizing assembler wasn't smart enough to do it that way.

Mel never wrote time-delay loops, either, even when the balky Flexowriter required a delay between output characters to work right. He just located instructions on the drum so each successive one was just *past* the read head when it was needed; the drum had to execute another complete revolution to find the next instruction. He coined an unforgettable term for this procedure. Although "optimum" is an absolute term, like "unique", it became common verbal practice to make it relative: "not quite optimum" or "less optimum" or "not very optimum". Mel called the maximum time-delay locations the "most pessimum".

After he finished the blackjack program and got it to run ("Even the initializer is optimized", he said proudly), he got a Change Request from the sales department. The program used an elegant (optimized) random number generator to shuffle the "cards" and deal from the "deck", and some of the salesmen felt it was too fair, since sometimes the customers lost. They wanted Mel to modify the program so, at the setting of a sense switch on the console, they could change the odds and let the customer win.

Mel balked. He felt this was patently dishonest, which it was, and that it impinged on his personal integrity as a programmer, which it did, so he refused to do it. The Head Salesman talked to Mel, as did the Big Boss and, at the boss's urging, a few Fellow Programmers. Mel finally gave in and wrote the code, but he got the test backwards, and, when the sense switch was turned on, the program would cheat, winning every time. Mel was delighted with this, claiming his subconscious was uncontrollably ethical, and adamantly refused to fix it.

After Mel had left the company for greener pa$ture$, the Big Boss asked me to look at the code and see if I could find the test and reverse it. Somewhat reluctantly, I agreed to look. Tracking Mel's code was a real adventure.

I have often felt that programming is an art form, whose real value can only be appreciated by another versed in the same arcane art; there are lovely gems and brilliant coups hidden from human view and admiration, sometimes forever, by the very nature of the process. You can learn a lot about an individual just by reading through his code, even in hexadecimal. Mel was, I think, an unsung genius.

Perhaps my greatest shock came when I found an innocent loop that had no test in it. No test. *None*. Common sense said it had to be a closed loop, where the program would circle, forever, endlessly. Program control passed right through it, however, and safely out the other side. It took me two weeks to figure it out.

The RPC-4000 computer had a really modern facility called an index register. It allowed the programmer to write a program loop that used an indexed instruction inside; each time through, the number in the index register was added to the address of that instruction, so it would refer to the next datum in a series. He had only to increment the index register each time through. Mel never used it.

Instead, he would pull the instruction into a machine register, add one to its address, and store it back. He would then execute the modified instruction right from the register. The loop was written so this additional execution time was taken into account --- just as this instruction finished, the next one was right under the drum's read head, ready to go. But the loop had no test in it.

The vital clue came when I noticed the index register bit, the bit that lay between the address and the operation code in the instruction word, was turned on --- yet Mel never used the index register, leaving it zero all the time. When the light went on it nearly blinded me.

He had located the data he was working on near the top of memory --- the largest locations the instructions could address --- so, after the last datum was handled, incrementing the instruction address would make it overflow. The carry would add one to the operation code, changing it to the next one in the instruction set: a jump instruction. Sure enough, the next program instruction was in address location zero, and the program went happily on its way.

I haven't kept in touch with Mel, so I don't know if he ever gave in to the flood of change that has washed over programming techniques since those long-gone days. I like to think he didn't. In any event, I was impressed enough that I quit looking for the offending test, telling the Big Boss I couldn't find it. He didn't seem surprised.

When I left the company, the blackjack program would still cheat if you turned on the right sense switch, and I think that's how it should be. I didn't feel comfortable hacking up the code of a Real Programmer.

This is one of hackerdom's great heroic epics, free verse or no. In a few spare images it captures more about the esthetics and psychology of hacking than all the scholarly volumes on the subject put together. For an opposing point of view, see the entry for {real programmer}.

[1992 postscript --- the author writes: "The original submission to the net was not in free verse, nor any approximation to it --- it was straight prose style, in non-justified paragraphs. In bouncing around the net it apparently got modified into the `free verse' form now popular. In other words, it got hacked on the net. That seems appropriate, somehow."]

:Appendix B: A Portrait of J. Random Hacker *******************************************

This profile reflects detailed comments on an earlier `trial balloon' version from about a hundred USENET respondents. Where comparatives are used, the implicit `other' is a randomly selected segment of the non-hacker population of the same size as hackerdom.

An important point: Except in some relatively minor respects such as slang vocabulary, hackers don't get to be the way they are by imitating each other. Rather, it seems to be the case that the combination of personality traits that makes a hacker so conditions one's outlook on life that one tends to end up being like other hackers whether one wants to or not (much as bizarrely detailed similarities in behavior and preferences are found in genetic twins raised separately).

:General Appearance: ====================

Intelligent. Scruffy. Intense. Abstracted. Surprisingly for a sedentary profession, more hackers run to skinny than fat; both extremes are more common than elsewhere. Tans are rare.

:Dress: =======

Casual, vaguely post-hippie; T-shirts, jeans, running shoes, Birkenstocks (or bare feet). Long hair, beards, and moustaches are common. High incidence of tie-dye and intellectual or humorous `slogan' T-shirts (only rarely computer related; that would be too obvious).

A substantial minority prefers `outdoorsy' clothing --- hiking boots ("in case a mountain should suddenly spring up in the machine room", as one famous parody put it), khakis, lumberjack or chamois shirts, and the like.

Very few actually fit the `National Lampoon' Nerd stereotype, though it lingers on at MIT and may have been more common before 1975. These days, backpacks are more common than briefcases, and the hacker `look' is more whole-earth than whole-polyester.

Hackers dress for comfort, function, and minimal maintenance hassles rather than for appearance (some, perhaps unfortunately, take this to extremes and neglect personal hygiene). They have a very low tolerance of suits and other `business' attire; in fact, it is not uncommon for hackers to quit a job rather than conform to a dress code.

Female hackers almost never wear visible makeup, and many use none at all.

:Reading Habits: ================

Omnivorous, but usually includes lots of science and science fiction. The typical hacker household might subscribe to `Analog', `Scientific American', `Co-Evolution Quarterly', and `Smithsonian'. Hackers often have a reading range that astonishes liberal arts people but tend not to talk about it as much. Many hackers spend as much of their spare time reading as the average American burns up watching TV, and often keep shelves and shelves of well-thumbed books in their homes.

:Other Interests: =================

Some hobbies are widely shared and recognized as going with the culture: science fiction, music, medievalism (in the active form practiced by the Society for Creative Anachronism and similar organizations), chess, go, backgammon, wargames, and intellectual games of all kinds. (Role-playing games such as Dungeons and Dragons used to be extremely popular among hackers but they lost a bit of their luster as they moved into the mainstream and became heavily commercialized.) Logic puzzles. Ham radio. Other interests that seem to correlate less strongly but positively with hackerdom include linguistics and theater teching.

:Physical Activity and Sports: ==============================

Many (perhaps even most) hackers don't follow or do sports at all and are determinedly anti-physical. Among those who do, interest in spectator sports is low to non-existent; sports are something one *does*, not something one watches on TV.

Further, hackers avoid most team sports like the plague (volleyball is a notable exception, perhaps because it's non-contact and relatively friendly). Hacker sports are almost always primarily self-competitive ones involving concentration, stamina, and micromotor skills: martial arts, bicycling, auto racing, kite flying, hiking, rock climbing, aviation, target-shooting, sailing, caving, juggling, skiing, skating (ice and roller). Hackers' delight in techno-toys also tends to draw them towards hobbies with nifty complicated equipment that they can tinker with.

:Education: ===========

Nearly all hackers past their teens are either college-degreed or self-educated to an equivalent level. The self-taught hacker is often considered (at least by other hackers) to be better-motivated, and may be more respected, than his school-shaped counterpart. Academic areas from which people often gravitate into hackerdom include (besides the obvious computer science and electrical engineering) physics, mathematics, linguistics, and philosophy.

:Things Hackers Detest and Avoid: =================================

IBM mainframes. Smurfs, Ewoks, and other forms of offensive cuteness. Bureaucracies. Stupid people. Easy listening music. Television (except for cartoons, movies, the old "Star Trek", and the new "Simpsons"). Business suits. Dishonesty. Incompetence. Boredom. COBOL. BASIC. Character-based menu interfaces.

:Food: ======

Ethnic. Spicy. Oriental, esp. Chinese and most esp. Szechuan, Hunan, and Mandarin (hackers consider Cantonese vaguely d'eclass'e). Hackers prefer the exotic; for example, the Japanese-food fans among them will eat with gusto such delicacies as fugu (poisonous pufferfish) and whale. Thai food has experienced flurries of popularity. Where available, high-quality Jewish delicatessen food is much esteemed. A visible minority of Southwestern and Pacific Coast hackers prefers Mexican.

For those all-night hacks, pizza and microwaved burritos are big. Interestingly, though the mainstream culture has tended to think of hackers as incorrigible junk-food junkies, many have at least mildly health-foodist attitudes and are fairly discriminating about what they eat. This may be generational; anecdotal evidence suggests that the stereotype was more on the mark 10--15 years ago.

:Politics: ==========

Vaguely left of center, except for the strong libertarian contingent which rejects conventional left-right politics entirely. The only safe generalization is that hackers tend to be rather anti-authoritarian; thus, both conventional conservatism and `hard' leftism are rare. Hackers are far more likely than most non-hackers to either (a) be aggressively apolitical or (b) entertain peculiar or idiosyncratic political ideas and actually try to live by them day-to-day.

:Gender and Ethnicity: ======================

Hackerdom is still predominantly male. However, the percentage of women is clearly higher than the low-single-digit range typical for technical professions, and female hackers are generally respected and dealt with as equals.

In the U.S., hackerdom is predominantly Caucasian with strong minorities of Jews (East Coast) and Orientals (West Coast). The Jewish contingent has exerted a particularly pervasive cultural influence (see {Food}, above, and note that several common jargon terms are obviously mutated Yiddish).

The ethnic distribution of hackers is understood by them to be a function of which ethnic groups tend to seek and value education. Racial and ethnic prejudice is notably uncommon and tends to be met with freezing contempt.

When asked, hackers often ascribe their culture's gender- and color-blindness to a positive effect of text-only network channels, and this is doubtless a powerful influence. Also, the ties many hackers have to AI research and SF literature may have helped them to develop an idea of personhood that is inclusive rather than exclusive --- after all, if one's imagination readily grants full human rights to AI programs, robots, dolphins, and extraterrestrial aliens, mere color and gender can't seem very important any more.

:Religion: ==========

Agnostic. Atheist. Non-observant Jewish. Neo-pagan. Very commonly, three or more of these are combined in the same person. Conventional faith-holding Christianity is rare though not unknown.

Even hackers who identify with a religious affiliation tend to be relaxed about it, hostile to organized religion in general and all forms of religious bigotry in particular. Many enjoy `parody' religions such as Discordianism and the Church of the SubGenius.

Also, many hackers are influenced to varying degrees by Zen Buddhism or (less commonly) Taoism, and blend them easily with their `native' religions.

There is a definite strain of mystical, almost Gnostic sensibility that shows up even among those hackers not actively involved with neo-paganism, Discordianism, or Zen. Hacker folklore that pays homage to `wizards' and speaks of incantations and demons has too much psychological truthfulness about it to be entirely a joke.

:Ceremonial Chemicals: ======================

Most hackers don't smoke tobacco, and use alcohol in moderation if at all (though there is a visible contingent of exotic-beer fanciers, and a few hackers are serious oenophiles). Limited use of non-addictive psychedelic drugs, such as cannabis, LSD, psilocybin, and nitrous oxide, etc., used to be relatively common and is still regarded with more tolerance than in the mainstream culture. Use of `downers' and opiates, on the other hand, appears to be particularly rare; hackers seem in general to dislike drugs that `dumb them down'. On the third hand, many hackers regularly wire up on caffeine and/or sugar for all-night hacking runs.

:Communication Style: =====================

See the discussions of speech and writing styles near the beginning of this File. Though hackers often have poor person-to-person communication skills, they are as a rule extremely sensitive to nuances of language and very precise in their use of it. They are often better at writing than at speaking.

:Geographical Distribution: ===========================

In the United States, hackerdom revolves on a Bay Area-to-Boston axis; about half of the hard core seems to live within a hundred miles of Cambridge (Massachusetts) or Berkeley (California), although there are significant contingents in Los Angeles, in the Pacific Northwest, and around Washington DC. Hackers tend to cluster around large cities, especially `university towns' such as the Raleigh-Durham area in North Carolina or Princeton, New Jersey (this may simply reflect the fact that many are students or ex-students living near their alma maters).

:Sexual Habits: ===============

Hackerdom tolerates a much wider range of sexual and lifestyle variation than the mainstream culture. It includes a relatively large gay and bi contingent. Hackers are somewhat more likely to live in polygynous or polyandrous relationships, practice open marriage, or live in communes or group houses. In this, as in general appearance, hackerdom semi-consciously maintains `counterculture' values.

:Personality Characteristics: =============================

The most obvious common `personality' characteristics of hackers are high intelligence, consuming curiosity, and facility with intellectual abstractions. Also, most hackers are `neophiles', stimulated by and appreciative of novelty (especially intellectual novelty). Most are also relatively individualistic and anti-conformist.

Although high general intelligence is common among hackers, it is not the sine qua non one might expect. Another trait is probably even more important: the ability to mentally absorb, retain, and reference large amounts of `meaningless' detail, trusting to later experience to give it context and meaning. A person of merely average analytical intelligence who has this trait can become an effective hacker, but a creative genius who lacks it will swiftly find himself outdistanced by people who routinely upload the contents of thick reference manuals into their brains. [During the production of the book version of this document, for example, I learned most of the rather complex typesetting language TeX over about four working days, mainly by inhaling Knuth's 477-page manual. My editor's flabbergasted reaction to this genuinely surprised me, because years of associating with hackers have conditioned me to consider such performances routine and to be expected. --- ESR]

Contrary to stereotype, hackers are *not* usually intellectually narrow; they tend to be interested in any subject that can provide mental stimulation, and can often discourse knowledgeably and even interestingly on any number of obscure subjects --- if you can get them to talk at all, as opposed to, say, going back to their hacking.

It is noticeable (and contrary to many outsiders' expectations) that the better a hacker is at hacking, the more likely he or she is to have outside interests at which he or she is more than merely competent.