“ This book (a 1982 Pulitzer Prize winner) documents the adventure of the design of a new Data General computer, the MV-8000 Eagle. It is an amazingly well-done portrait of the hacker mindset — although largely the hardware hacker — done by a complete outsider. It is a bit thin in spots, but with enough technical information to be entertaining to the serious hacker while providing non-technical people a view of what day-to-day life can be like — the fun, the excitement, the disasters. ”

“ Those days of innocence are gone forever; society's adaptation to the advent of the microcomputer after 1980 included the elevation of the hacker as a new kind of folk hero, and the result is that some people semi-consciously set out to *be hackers* and borrow hackish prestige by fitting the popular image of hackers. ”

“ Often the computer can access its memory once on every clock cycle, and so one speaks also of `memory cycles'. These are technical meanings of {cycle}. The jargon meaning comes from the observation that there are only so many cycles per second, and when you are sharing a computer the cycles get divided up among the users. The more cycles the computer spends working on your program rather than someone else's, the faster your program will run. That's why every hacker wants more cycles: so he can spend less time waiting for the computer to respond. ”

“ If you catch a newspaper or magazine abusing the work `hacker', write them and straigten them out (this appendix includes a model letter) .
* If you're a techie or computer hobbyist, get involved with one of the free Unixes. Toss out that lame Microsoft OS, or confine it to one disk partition and put Linux or FreeBSD or NetBSD on the other one. And the next time your friend or boss is thinking about some commercial software `solution' that costs more than it's worth, be ready to blow the competition away with free software running over a free Unix. ”

“ People who use Pascal for serious programming fall into a fatal trap. Because the language is impotent, it must be extended. But each group extends Pascal in its own direction, to make it look like whatever language they really want. Extensions for separate compilation, FORTRAN-like COMMON, string data types, internal static variables, initialization, octal numbers, bit operators, etc., all add to the utility of the language for one group but destroy its portability to others. ”

“ On the ITS system there was a program that allowed you to see what was being printed on someone else's terminal. It spied on the other guy's output by examining the insides of the monitor system. The output spy program was called OS. Throughout the rest of the computer science (and at IBM too) OS means `operating system', but among old-time ITS hackers it almost always meant `output spy'.
OS could work because ITS purposely had very little in the way of `protection' that prevented one user from trespassing on another's areas. Fair is fair, however. ”

“ Semantically, one rich source of jargon constructions is the hackish tendency to anthropomorphize hardware and software. This isn't done in a naive way; hackers don't personalize their stuff in the sense of feeling empathy with it, nor do they mystically believe that the things they work on every day are `alive'. What *is* common is to hear hardware or software talked about as though it has homunculi talking to each other inside it, with intentions and desires. ”

“ Among hackers, accordingly, the word has a pejorative connotation. It is typically used of a project, especially one in artificial intelligence research, that is written up in grand detail (typically as a Ph.D. thesis) without ever being implemented to any great extent. Such a project is usually perpetrated by people who aren't very good hackers or find programming distasteful or are just in a hurry. A `gedanken thesis' is usually marked by an obvious lack of intuition about what is programmable and what is not, and about what does and does not constitute a clear specification of an algorithm. ”

“ The wide-area-networking protocol that makes the Internet work, and the only one most hackers can speak the name of without laughing or retching. Unlike such allegedly `standard' competitors such as X.25, DECnet, and the ISO 7-layer stack, TCP/IP evolved primarily by actually being *used*, rather than being handed down from on high by a vendor or a heavily-politicized standards committee. Consequently, it (a) works, (b) actually promotes cheap cross-platform connectivity, and (c) annoys the hell out of corporate and governmental empire-builders everywhere. ”

“ The general theory behind this term is that there are two classes of people who work with a program: there are implementors (hackers) and {luser}s. The users are looked down on by hackers to some extent because they don't understand the full ramifications of the system in all its glory. (The few users who do are known as `real winners'.) The term is a relative one: a skilled hacker may be a user with respect to some program he himself does not hack. ”

“ When talking about the jargon there is therefore no convenient way to distinguish it from what a *linguist* would call hackers' jargon —- the formal vocabulary they learn from textbooks, technical papers, and manuals.
To make a confused situation worse, the line between hacker slang and the vocabulary of technical programming and computer science is fuzzy, and shifts over time. Further, this vocabulary is shared with a wider technical culture of programmers, many of whom are not hackers and do not speak or recognize hackish slang. ”

“ The hack may qualify as `Unix brain damage' if the program conforms to published standards and the Unix program in question does not. Unix brain damage happens because it is much easier for other (minority) systems to change their ways to match non-conforming behavior than it is to change all the hundreds of thousands of Unix systems out there.
An example of Unix brain damage is a {kluge} in a mail server to recognize bare line feed (the Unix newline) as an equivalent form to the Internet standard newline, which is a carriage return followed by a line feed. ”

“ Most hackers subscribe to the hacker ethic in sense 1, and many act on it by writing and giving away free software. A few go further and assert that *all* information should be free and *any* proprietary control of it is bad; this is the philosophy behind the {GNU} project.
Sense 2 is more controversial: some people consider the act of cracking itself to be unethical, like breaking and entering. But the belief that `ethical' cracking excludes destruction at least moderates the behavior of people who see themselves as `benign' crackers (see also {samurai}) . ”

“ 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. ”

“ Hackers tend not to think of the things they themselves run as apps; thus, in hacker parlance the term excludes compilers, program editors, games, and messaging systems, though a user would consider all those to be apps. (Broadly, an app is often a self-contained environment for performing some well-defined task such as `word processing'; hackers tend to prefer more general-purpose tools.) See {killer app}; oppose {tool}, {operating system}.
:arena: [Unix] /n./ The area of memory attached to a process by `brk (2) ' and `sbrk (2) ' and used by `malloc (3) ' as dynamic storage. ”

“ The first machine to discover the down one is now trying both to access the down one and to respond to the pseudo-down one, so it is even harder to reach. This situation snowballs very quickly, and soon the entire network of machines is frozen — worst of all, the user can't even abort the file access that started the problem! Many of NFS's problems are excused by partisans as being an inevitable result of its statelessness, which is held to be a great feature (critics, of course, call it a great {misfeature}) . ”

“ It was obviously a homebrew job, added by one of the lab's hardware hackers (no one knows who) .
You don't touch an unknown switch on a computer without knowing what it does, because you might crash the computer. The switch was labeled in a most unhelpful way. It had two positions, and scrawled in pencil on the metal switch body were the words `magic' and `more magic'. The switch was in the `more magic' position.
I called another hacker over to look at it. He had never seen the switch before either. Closer examination revealed that the switch had only one wire running to it! ”

“ Because hackerdom is an intentional culture (one each individual must choose by action to join) , one should not be surprised that the line between description and influence can become more than a little blurred. Earlier versions of the Jargon File have played a central role in spreading hacker language and the culture that goes with it to successively larger populations, and we hope and expect that this one will do likewise. ”

“ Historically, back doors have often lurked in systems longer than anyone expected or planned, and a few have become widely known. Ken Thompson's 1983 Turing Award lecture to the ACM admitted the existence of a back door in early Unix versions that may have qualified as the most fiendishly clever security hack of all time. In this scheme, the C compiler contained code that would recognize when the `login' command was being recompiled and insert some code recognizing a password chosen by Thompson, giving him entry to the system whether or not an account had been created for him. ”

“ Death code isn't very useful, but writing it is an interesting hacking challenge on architectures where the instruction set makes it possible, such as the PDP-8 (it has also been done on the DG Nova) .
Perhaps the ultimate death code is on the TI 990 series, where all registers are actually in RAM, and the instruction "store immediate 0" has the opcode "0". The PC will immediately wrap around core as many times as it can until a user hits HALT. Any empty memory location is death code. ”

“ Mailing lists are easy to create and (unlike Usenet) don't tie up a significant amount of machine resources (until they get very large, at which point they can become interesting torture tests for mail software) . Thus, they are often created temporarily by working groups, the members of which can then collaborate on a project without ever needing to meet face-to-face. Much of the material in this lexicon was criticized and polished on just such a mailing list (called `jargon-friends') , which included all the co-authors of Steele-1983. ”

“ As usual with slang, the special vocabulary of hackers helps hold their culture together — it helps hackers recognize each other's places in the community and expresses shared values and experiences. Also as usual, *not* knowing the slang (or using it inappropriately) defines one as an outsider, a mundane, or (worst of all in hackish vocabulary) possibly even a {suit}. All human cultures use slang in this threefold way — as a tool of communication, and of inclusion, and of exclusion. ”