Great but not good? "Put a pulse to the hooter"

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From "CLAUDE E. SHANNON: An Interview Conducted by Robert Price, 28 July 1982":

[Shannon is talking about a visit to Alan Turing in Manchester in 1950.]  So I asked him what he was doing. And he said he was trying to find a way to get better feedback from a computer so he would know what was going on inside the computer. And he’d invented this wonderful command. See, in those days they were working with individual commands. And the idea was to discover good commands. And I said, what is the command? And he said, the command is put a pulse to the hooter, put a pulse to the hooter. Now let me translate that. A hooter is an English, in England is a loudspeaker. And by putting a pulse to it, it would just be put a pulse to a hooter. Now what good is this crazy command? Well, the good of this command is that if you’re in a loop you can have this command in that loop and every time it goes around the loop it will put a pulse in and you will hear a frequency equal to how long it takes to go around that loop. And then you can put another one in some bigger loop and so on. And so you’ll hear all of this coming on and you’ll hear this “boo boo boo boo boo boo,”[CS vocalizing in a sing-song fashion] and his concept was that you would soon learn to listen to that and know whether when it got hung up in a loop or something else or what it was doing all this time, which he’d never been able to tell before. That was a great idea, but I don’t think it was really a very good idea. That command seems to have disappeared from the vocabulary. [laughs]

These days you'd just have the program write out status updates, I guess.

There was a time when the state of your program could be seen (and modified!) via a large panel of blinking lights connected to register bits and other things, as in this picture of the operator's panel for the DDP-224 we used at Bell Labs when I first worked there (shown behind Laurie Spiegel in another image):

When we switched to a PDP-11, whose console was less informative and also was in another room, someone arranged to place two cables next to each other — one of them connected the computer to the external disk drive (a machine about the size of a washing-machine that could store a full 1.5 megabytes), and the other one provided input to an amplifier connected to the audio output system.

Through the magic of electromagnetic induction, we could then hear variable-rate clicking and chittering and humming as the machine went through various stages of a process.



  1. Gregory Kusnick said,

    March 23, 2019 @ 1:51 pm

    Back in the 1970s I worked in a lab where we had individual computers (the size of a hotel minibar) that used 15" removable disk packs (about the capacity of a 3" floppy). Running a software build on these machines could take upwards of 20 minutes, but I soon learned to recognize when the build was almost done by the distinctive pattern of audible disk seeks as it wrote out the final executable.

  2. Philip Taylor said,

    March 23, 2019 @ 4:15 pm

    And, within the last couple of months, I was able to tell when one of my Win-7 machines was about to freeze by the sound of the disk servo hunting …

  3. Ray said,

    March 23, 2019 @ 4:18 pm

    I love this! now we know what hooters can really do.

  4. David said,

    March 23, 2019 @ 5:39 pm

    Back when I was learning to build hardware (6502 cpu in the late 70's), we put a radio near the memory card and listened. The particular loop that we suffered from most frequently – if I can remember back that far – was a bug leading to an interrupt being called and the 6502 fetching the interrupt handler from high memory somewhere. The sounds the radio would spit out were quite identifiable when this was happening. While I'm struggling to remember the physical details of what was going on, the visceral feel of it came rushing back to me on reading that quote.

  5. Rick Rubenstein said,

    March 23, 2019 @ 5:53 pm

    It's interesting that English has no common, standard equivalent to "visualize" for audio. Converting data to an audio format in order to harness our (extremely sensitive) sound perception circuitry is fairly rare (and perhaps underutilized), but not so rare that it doesn't deserve a name.

  6. AntC said,

    March 23, 2019 @ 6:55 pm

    equivalent to "visualize" for audio.

    We have "vocalise" and "verbalise".

    As others above reminisce, yes back when I was a computer operator, I got to know the audio pattern of the 'nightly batch run'. I don't know if manufacturers deliberately put sound effects into their machines as per Turing, but they certainly didn't noise-suppress them.

    And Turing's 'hooter' persists to this day as ASCII 'Bell' ctrl-G.

  7. Narmitaj said,

    March 23, 2019 @ 7:28 pm

    "That was a great idea, but I don’t think it was really a very good idea."

    The text seems like a verbatim and untidied record of what was actually said (see also "A hooter is an English, in England is a loudspeaker").

    By "that was a great idea" I think CS was saying Turing had a great flash of inspiration aimed at filling a need. But by "I don’t think it was really a very good idea" I am guessing he meant that the detailed practicalities of learning to listen to these sounds and derive information from them might prove hard for the average user who is not-Turing, and a better way (like lights) would be preferable.

    Either that, or he was just complaining that implementing this hooter system universally would make for unfeasibly noisy computer labs, honking and tooting and parping all the time. If he had written the piece, perhaps he would have recast the phrase differently.

  8. MikeA said,

    March 23, 2019 @ 7:33 pm

    In the film Dr. Strangelove, Group Captain Lionel Mandrake discovers a transistor radio in a printer, and is thus able to understand that the rest of the U.S. is not "aware" of the impending Soviet attack (product of a mad base-commander)

    Those of a certain age (and nerdiness) would know why it was there. Besides writing programs to play "music" by picking up the variations in RF from, e.g. different length "Move" instruction, our most popular use was to stay in the room next to the computer room (which was kept at a temperature more comfortable for computers, or polar bears, than people), and listen to the radio. When the distinctive sound of the "waiting for a command" prompt was heard, it was time to put on the parka and go in to start the next job.

  9. mdhughes said,

    March 23, 2019 @ 8:39 pm

    Back in the '80s in BASIC on the Atari 8-bit computers, I'd use short sound synthesizer commands for debugging the same way: There was no console or other way to see something happening, but at least one sound channel was usually free. It could be as simple as "sound 3,x,10,8" for a tone based on some data. Later I'd go through and delete all the sound 3 commands.

    Now doing that is improbably difficult, making a waveform and playing it takes at least a utility library, or playing back a sound file. I just log text to a console.

    So that's another kind of linguistics: The words you have easy access to are the ones you use.

  10. Colin Rafferty said,

    March 23, 2019 @ 9:18 pm

    The modem we used to dial the ISPs would have beep and boop and brappp depending on the connection speed.

  11. maidhc said,

    March 24, 2019 @ 1:31 am

    Back in the old days, this could have worked pretty well, but as CPU speed went up, it would have gone out of the range of hearing. Thankfully, by then we had logic analyzers and digital oscilloscopes to help with problems of that nature.

  12. TIC said,

    March 25, 2019 @ 11:14 am

    It seems to me that "put a pulse to the hooter" is such a *great* accidental turn of phrase that it'd be a damn shame if it doesn't somehow live on… Maybe (perhaps in a shortened form) as a band name?… Or maybe as a (longish) euphemism for something?… I dunno… But it'd be a crime to let it die…

    Also, FWIW, 'a great idea but not a very good idea' seems to me every bit as legit as "I love you, but I don't like you"…

  13. Joe said,

    March 25, 2019 @ 11:15 am

    Put a pulse to the hooter to discover cryptographic keys:

  14. Peter said,

    March 29, 2019 @ 2:10 pm

    I worked as a computer operator during university vacations in the 1960s on ICL 1900 series computers, and they all had a coil somewhere near the processor connected to a small loudspeaker in the operator's console. Many tasks such as payroll ran for hours with frequent changes of tapes, and we all knew from the sounds when a tape change was coming up or when the task was about to complete.

  15. Andrew Usher said,

    March 30, 2019 @ 9:44 am

    As many have noted, diagnosing computer troubles by sound was and still is common. So dismissing the idea may have been premature.

    Oh, and in the phrase 'put a pulse to the hooter' it's the 'put' that is really the strangest – it is rarely ever used in that sense. I wonder if in the computer use it was regarded as a clipping of 'output', or at least influenced by it?

    k_over_hbarc at

  16. TIC said,

    March 31, 2019 @ 5:16 am

    Darnit, Andrew!… I try *so* hard not to overshare on LL my tendency to overthink and overanalyze unimportant things… (And then you just *had* to go and reopen this particular discussion!)… Sooo, now I feel compelled and emboldened to note that I find it quite interesting that of the three most prominent words in the salient phrase (‘put’, ‘pulse’, and ‘hooter’) the one that you focused on (‘put’) is the one to which I gave the least thought…

    When I read first read the excerpt, I gave more than a bit of thought to the facts that it’s from a now-decades-old interview with an American and it was a recounting of a then-decades-old discussion with a Brit… So, it includes aspects of AmE vs. BrE as well as a double dose of time travel… And, given its significance, it’s reasonable to assume that the salient phrase is an exact quote of Turing’s actual words…

    My initial thoughts were that in this context ‘pulse’ was/is likely a shortening of (electrical) ‘impulse’ and that the commonness of the word ‘hooter’ with this meaning has, at least in the US, declined over the decades… My impression is that, at least on this side of the pond, it was originally used mostly by audiophiles and other insiders (of which I’m not one) to refer not to just any (loud)speaker but more specifically to a smaller (low-range) bass speaker often paired with a larger (mid/high-range) speaker… It also occurred to me that, at least currently and among laymen in the US, it’s more common to simply use the word ‘speaker’ in this context and to use the word ‘loudspeaker’ only for large PA (public address) speakers mounted in outdoor and big indoor spaces…

    I gave little if any thought to the word ‘put’, probably because to me it doesn’t seem unnatural to think of ‘putting’ an electrical charge to, or load on, a wire or lead… So, when in an earlier comment I called “put a pulse to the hooter” a *great* accidental turn of phrase, I wasn’t giving much thought to the word ‘put’… And, finally, if I (a modern, AmE-speaking layman) were for some reason to have occasion to put into words what Turing was describing, I’d probably say something along the lines of a “send a signal to the speaker”…

    Other than all that, I didn’t give this post a moment’s (over)thought!…

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