Comments by "Lawrence D’Oliveiro" (@lawrencedoliveiro9104) on "Technology Connections" channel.

  1. 6:36 Probably good to mention by this point that “I” stood for “in-phase” and “Q” for “quadrature”. That is, these were the 0° and 90° components extracted from the phase-modulated chrominance signal. If you think of this signal as a point moving in two dimensions, the direction of the point from the centre gives you the hue, and the distance from the centre is the saturation of the colour.
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  2. 12:05 It becomes easier to tell once the percussion and rhythm kick in. Full-spectrum sound really brings out the difference.
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  3. 13:10 I’m sure “minus” was a term promoted by the Sony/Philips group just to make the DVD Forum grit their teeth every time they heard it. ;)
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  4. 6:53 Actually you’ve got it upside down; higher signal levels correspond to lower luminance levels (darker), while lower levels are higher (lighter). It was done this way so that transients caused by interference would random dark dots instead of random light dots, and the former were considered to be less noticeable.
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  5. 5:14 Rust (FeO, Fe₂O₃) is not magnetic (much). The iron oxide used in magnetic tape is magnetite, Fe₃O₄. Oh, and it also appears they use the γ-form of Fe₂O₃ (maghemite).
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  6. 7:03 What’s really bad is that the second r in “Corporation” is not capitalized as well. “TelePrompTer CorpoRation” ... now isn’t that better?
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  7. There was the time I lost my grip on reality ... oh wait, that never happened.
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  8. 3:06 You don’t get two dings as the toast is going down? (Sorry, just been watching your elevator-sound video.)
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  9. A “magitain’t”. Or “magnitain’t”.
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  10. 13:15 So when did “amber” enter the language? “Gamboge”?
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  11. 0:51 There is a similar thing in book/magazine printing called “imposition”. This is where you arrange the printing of pages in fours on double-width sheets so that when they are folded in the middle and stacked and bound together, the page numbers end up in the correct sequence.
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  12. 4:45 “Not a questionable astronomical unit” ... so, not less than 12 parsecs, then?
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  13. IBM Selectrics were also often adapted for use as computer output devices. It was basically a matter of replacing the printing electronics that were driven by the keys, with circuits that could be driven by impulses from the computer.
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  14. 14:50 It’s not two “sides”: the tracks are still on the same side of the tape. They are simply positioned in-between the tracks recorded in the other direction. So you have four tracks along the length of the tape — two stereo pairs, recorded in opposite directions.
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  15. “Computers” have been around for centuries. The term used to mean “person who did calculations”, before machines did them.
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  16. There were two different quadraphonic systems. There was SQ, a “matrix” system which didn’t really have four separate channels, and there was JVC’s CD-4, which used subcarriers to encode either the rear channels or front/rear difference signals, not sure which. This gave better channel separation. I remember reading a bunch of Sansui brochures at the time. They took SQ and turned it into “QS”, which some kind of dynamic level-based adjustments of the decoding matrix, to give the effect of better apparent channel separation.
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  17. Particularly since PC hard drives of the period were only on the order of tens of megabytes. This was a particular issue to those trying to create CD-ROMs. Even when DVDs first came out, they held more than the common hard drive capacity, though the ratio was smaller. By about the ’00s, hard drives had overtaken optical media and left them in the dust.
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  18. 0:47 Only a dozen? Kids’ stuff. /me remembers SCSI connectors with 50 wires (OK, 25 signal wires plus 25 ground wires).
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  19. All you need to know is, it dates from the era when Apple were still a technological pioneer.
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  20. 2:14 Is that Spanish for “/dev/null”?
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  21. Such a filter on the output side is called the “reconstruction filter”, while on the input side it is called the “antialiasing filter”. In both cases, their job is to get rid of spurious frequencies above the Nyquist limit. The reconstruction filter is a “usually-good-enough” approximation to the ideal sinc reconstruction function.
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  22. Digital is robust against errors up to a point, then it completely falls apart. Analog suffers from the slightest error, but the degradation is gradual all the way down from there, rather than falling off a cliff. You pays yer money and you takes yer choice.
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  23. 4:52 “1.44” ... Q: is that megabytes or mebibytes? A: Neither.
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  24. Things not to google, #934: “Two girls, one blue jiggly”.
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  25. 5:28 “Precisely” ... now there’s a word you didn’t hear much in connection with consumer-quality analog video formats ...
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  26. 1:24 /me puts a picture representing the Second Law of Thermodynamics up on a dartboard and proceeds to throw darts at it.
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  27. “Pulling out all the stops” is when you want maximum sound from an organ.
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  28.  @tomasbickel58  The light reflects from below towards the presenter, not towards the lens.
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  29. 12:42 That whole “will it play on my VCR?” argument from the VHS-C camp was never really convincing. TVs and living-room VCRs both soon added extra AV inputs on the side, to make it easy to plug in your camcorder. And you had to copy to do editing anyway. I think worldwide Video-8 and Hi-8 outsold VHS-C and S-VHS-C. Also the extra recording time didn’t hurt.
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  30. Are you sure it was FEC? I remember being in my uncle’s place years ago (he was a radio ham) and hearing some digital data communication being monitored on his gear: you could distinctly hear the packet being transmitted, followed by the acknowledgement, then another packet etc. Seemed like a waste of bandwidth. I told them they should do a TCP-style sliding-window protocol, to allow multiple packets to be sent before receiving the acknowledgements, to get around the channel latency.
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  31. 2:01 Some people (lucky tetrachromats) get to see four. They seem to be mostly women.
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  32. 0:24 “Trying my hardest ... low-effort” ... how to succeed at deadpan humour without really trying ...
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  33. History repeats, doesn’t it?
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  34. 2:19 Shape ... kinda like a loaf of bread ...
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  35. ... Adobe sits quietly, twiddling thumbs and making “ka-ching” noises ...
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  36. There were never “CD+R/RW” formats. You’re thinking of DVD+R/RW.
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  37. →C64 C64 There was no “time delay” in PAL. It solved the colour problem in a very simple and elegant way, which is why it became the world’s most popular broadcast colour TV system.
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  38. You are confusing the spec with implementations of the spec. Quoth Wikipedia <https://en.wikipedia.org/wiki/PAL>: “Early PAL receivers relied on the human eye to do that cancelling; however, this resulted in a comb-like effect known as Hanover bars on larger phase errors. Thus, most receivers now use a chrominance analog delay line, which stores the received colour information on each line of display; an average of the colour information from the previous line and the current line is then used to drive the picture tube. The effect is that phase errors result in saturation changes, which are less objectionable than the equivalent hue changes of NTSC.”
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  39. Teletext: such a hack that, if the signal quality degrades, it will be the first thing to go. You know what really was a marvel in the days of analog TV? NICAM digital stereo sound, that’s what.
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  40. 8:20 Surely there must already be some open-source text-scrolling software for Linux or Android. How hard could it be to write?
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  41. That tune somehow takes me back to being at an audio hi-fi store sometime in the 1970s, listening to a demo of this new thing called “quadraphonic” ...
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  42.  @KaitouKaiju  Their word was “elektron”.
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  43. 8:35 Spoiler alert ... . . . . . Keep an eye on the colour of the Mac’s desktop background.
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  44. 4:27 “Arabicadabra” ... heh-heh.
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  45. That meaning is from pipe-organ technology, from a few centuries before photography. #LanguageGeek #PunSpoilSport
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  46. The ideal reconstruction involves plotting something called a “sinc function” centred at each sample, then adding up all these curves. The trouble with this ideal is that the sinc function has an infinite extent and only slowly fades to zero as you get further from the centre.
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  47. 1:07 It is quite possible to do differential signalling over copper, with isolation at each end to block the ground loops. Venerable old MIDI works this way—optoisolators at each end are a mandatory part of the standard.
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  48. 3:15 12,000 in 1927 units? How many would that be in 2019 numbers? (Well, had to get back at you for that “playing records upside-down” dig ...)
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  49. Here in Mathland, quaternions break into you.
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  50.  @DeviantOllam  I remember Watch Mr Wizard being on t’telly when I were a wee lad back in the old country. I remember very few details about the episodes, except the one where he demonstrated an atomic chain reaction using an aquarium full of ping-pong balls sitting on armed mousetraps. Incidentally, Jim Al-Khalili did the same demo.
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