mrandish 2 months ago | next |

Several years ago I came across the first issue of "Television" magazine from 1928 and reading it blew my mind in a couple ways. First, the overall tone is remarkably similar to a 1970s homebrew computer club newsletter, including defining what "television" even is (and isn't). For example, We learn on page 10 that "television is not tele-photography."

It's clear from this magazine that early television was the domain of home tinkerers and hackers. On page 26 is a detailed tutorial on how to construct your own selenium condenser cell from scratch, including which London chemist had appropriately high-quality selenium, where to buy copper sheets, mica insulator (.008 thick) and brass bars. Well worth a read: https://comicbookplus.com/?dlid=37097

That analog television not only was prototyped nearly a hundred years ago but then began being deployed at vast consumer scale ~75 years ago is still just so amazing. It's worth understanding a bit about how it works just to appreciate what a wildly ambitious hack it was. From real-time image acquisition to transmission to display, many of the fundamental technologies didn't even exist and had to be invented then perfected for it to work.

dTal 2 months ago | root | parent | next |

Although it's about wire transmission of photography - which, as pointed out, television is not - it's still well worth watching this 1937 newsreel explaining how it works, mostly because 1) they devote a LOT of time towards explaining the concept of scanning/rastering, which was clearly not widely intuited at the time, and 2) they do it with a brilliant physical analogy, with the incredible pedagogical clarity typical of such 1930s educational videos.

https://youtu.be/cLUD_NGE370?

IIAOPSW 2 months ago | root | parent |

First time I watched that I forgot I had the speed set to 1.5 or something so the already fast-talking 1930s mid-atlantic radio announcer voice got exaggerated to a hilarious degree. Especially funny as the first few lines were about the importance of speed!

readyplayernull 2 months ago | root | parent | prev | next |

So cool, it reminded me a book I once found and never seen again on building analog computers at home with a few bits of magnetic-core memory. That magazine even shows Osram tubes, I didn't know that brand had such long history. One of my desktop toys is a $5 Osram Tungsten bulb that I bought to "watch" the highest melting-point element emitting light.

nxobject 2 months ago | root | parent | prev |

It’s sad to imagine, though how the cutting edge of TV technology was always of the reach of homebrewers - especially after the consensus dismissed mechanical scanning in favor of electron gun-based scanning (developed almost simultaneously).

phkahler 2 months ago | prev | next |

Also interesting is the electromechanical "tone wheel generator" used in the Hammond Organs:

https://forums.musicplayer.com/topic/155607-a-look-inside-a-...

91 metal wheels with lobes spinning past something like electric guitar pickups to produce sine waves. Their goal was to produce pure sine waves and then combine them via "drawbars" to produce an adjustable sound. 12 different gear ratios and different number of lobes (powers of two) to produce all the frequencies.

The rotating "Leslie" speaker was also cool, as is the electromechanical "vibrato scanner" on later models.

aftbit 2 months ago | prev | next |

So much was done with mechanical systems back in the day, because they were better understood and comparatively cheaper than corresponding electrics. I wonder if the engineers who designed teletypes or artillery range computers could learn to program, and if they did, would they have any unique insights?

bee_rider 2 months ago | root | parent | next |

Krylov (the guy the subspaces are named after) was a naval engineer. Cholesky was an artillery officer.

tway_GdBRwW 2 months ago | root | parent |

I love this unique insight:

"Fire control computers ... solve ... fire control problems."

https://www.youtube.com/watch?v=gwf5mAlI7Ug

U.S. NAVY BASIC MECHANISMS OF FIRE CONTROL COMPUTERS MECHANICAL COMPUTER INSTRUCTIONAL FILM 27794

bee_rider 2 months ago | root | parent |

Those old educational videos are a lesson in how to give presentations I think. There’s an art to the way they build up a fairly complicated concept step by step. The viewers are starting from zero after all.

The starting step is one that is impossible to misunderstand. From there, go one concrete step to another.

082349872349872 2 months ago | root | parent | prev | next |

They'd probably take a dependency, slice out the quarter they actually use, and somehow turn it into a cleverly-encoded lookup table or two?

gradschoolfail 2 months ago | root | parent |

Hopefully, you didnt miss this tangentially moored submission (was your depedendency on time constant re: [VP] sales vs engineers related to that covered therein

https://news.ycombinator.com/item?id=41556915

082349872349872 2 months ago | root | parent |

No, I was referring to a different time constant: the τ such that the number of times the whiskey priest[0] falls off the wagon[1] occuring at t<τ equals the number of times the decay occurs at t>τ.

So, just like the quantum watched pot never boils, the up-through-sales CEO would, out of habit alone, keep nurturing[2] their company officers — staying in touch (t<<τ) and shepherding them away from personal and towards corporate goals.

(My hypothesis being that an up-through-engineering CEO, not finding this behaviour natural, would have to make an explicit attempt to do so, and hence might experience severe cultural issues dealing with people who can deliver a great deal of value under the right leadership but require steady, if small[3][4], external inputs to keep them in the fold.)

[0] compare https://en.wikipedia.org/wiki/Don_Camillo_and_Peppone#Charac...

[1] pads headcount, orphans mistakes, etc.

[2] for a prospect: staying in touch and shepherding them towards close

[3] the shepherd's crook can be mightier than the prince's cannon. (back when we had Prince-Bishops they used to commission statues of themselves holding both sword and crook, emphasising their ability to use either temporal persuasion or moral suasion)

[4] see also the unstable yet controllable regime for designing fighter aircraft.

gradschoolfail 2 months ago | root | parent |

The designoris (as well as the B2C sales (“marketers”) whom they tend to relate more to) should also have a time constant, such that the dynamics of navigating these various time constants do not tend to elevate them to any inner party (e.g. in AAPL, designoris getting driven out..)

EDit: just saw that you replied to showrunning, thanks for directing my attention! I also replied to DG thread

Animats 2 months ago | root | parent | prev | next |

Feynman did some mechanical artillery range computer design. Read "Surely you're joking, Mr. Feynman". He has a few things to say about it.

WalterBright 2 months ago | root | parent | prev |

If you tour the British cruiser parked in the Thames in London, you can see the artillery computer. It's a triumph of mechanical computing.

Animats 2 months ago | prev | next |

There's a long history there. See the Early Television Museum.[1]

It's sad that no Scophony set survives. High resolution and 24 inch screens in 1938.

[1] http://earlytelevision.org/mechanical.html

xattt 2 months ago | root | parent |

> 2 mHz

TV broadcasts sure were frequency efficient.

avhon1 2 months ago | root | parent |

With pictures "made up of only 30 to 60 lines", they were transmitting much less data!

kragen 2 months ago | root | parent | next |

at two millihertz of bandwidth, you could transmit a 30-pixel line in only 7500 seconds, so you could transmit an entire 30×30 frame in 225 000 seconds, less than three days

but plausibly the millihertz notation was an error and megahertz was meant

mrguyorama 2 months ago | root | parent | prev |

Full blown color NTSC managed with 6mhz channels! Digital broadcasts have a terrible user experience: Instead of providing the same channel they always did, but to vastly more receivers in much more marginal conditions using advances in digital signal processing and encoding power and methodology, broadcasters were allowed to cut up their frequency into 6 "subchannels", so they crunch the streams to the shittiest quality they can (as low as 3mb/s, DVD is 10!) legally get away with, provide almost zero redundancy in the broadcast, so now TVs that were well in the broadcast area of analog signals are straining to get every last bit out of the digital stream so it can hope to recover a picture.

They did this because 6 channels that most people cannot actually receive over the air gives them more advertisement slots than the 1 previous channel. Good old enshittification.

mrandish 2 months ago | root | parent | next |

> NTSC managed with 6mhz channels!

Not only did it manage, it looked fantastic, at least at the source. Back in the 80s I had a chance work with high-end analog video gear at a broadcast production studio. You wouldn't believe the detail and color fidelity of a full 6 Mhz composite video signal coming straight out of a broadcast studio camera through a Grass Valley video switcher to a studio reference monitor. It had a lot of the subjective character audiophiles use to describe tube amplifiers like: depth, warmth, etc. After being recorded on a 2-inch broadcast quad tape machine (the size of a dishwasher!), the playback looked identical to my eyes.

Of course, by the time these pristine images lost several generations through editing and dubbing, were sent through RF distribution, up a transmitter, down an antenna and through 75 ohm coax house cable, they could look decidedly less amazing. :-)

In the 90s, analog component video looked even more impressive still and we could record and dub it digitally on D1 digital VTRs with no generational loss (and no compression!). Since so much of the analog standard definition TV historical footage we see today was recorded post-edit & dubbing and then captured on VHS or 3/4-inch U-Matic tape air checks, it doesn't reflect the remarkable quality we had back then. And worse, much of what we see today of analog video is also not properly de-interlaced during digital conversion and then is further degraded through over-compression for streaming or broadcast. The worst of all worlds...

To your point, the quality we had back then makes the peggish mess created by today's over-compression all the more egregious. I have a high-end 4K HDR10 home theater with top notch components all properly interfaced, calibrated and tested - and yet, outside of 4K Ultra HD discs, much of what I see on OTA broadcast, cable, satellite and streaming looks pretty awful.

rescbr 2 months ago | root | parent |

> and yet, outside of 4K Ultra HD discs, much of what I see on OTA broadcast, cable, satellite and streaming looks pretty awful.

And that's why I keep my grandfathered Netflix 720p subscription. Shitty compression with low resolution vs shitty compression with higher resolution means the same amount of artifacts anyway.

JadeNB 2 months ago | root | parent | prev |

> Full blown color NTSC managed with 6mhz channels!

I think that the point was that 2 (or 6) mHz is a much lower frequency than 2 (or 6) MHz, and the latter is almost surely what was meant.

andrehacker 2 months ago | prev | next |

There is a great model kit made in England for the "Televisor". Got it years ago and it was minutes of fun. Apparently still for sale. The input is audio, got it to run from my iphone at the time (as opposed to using the supplied CD which in itself is Retro technology). I had some plans to build code a video-to-audio converter to run this (or screengrab to audio for that matter).

https://www.youtube.com/watch?v=fTSeUjvScUA

YeGoblynQueenne 2 months ago | prev | next |

>> My Greek teacher hated the word “television.” He considered it an abomination that combined the Greek prefix telos (far off) with a Latin base, videre (to see).

Note "telos" which means 'goal' or 'end', but "tele-" which indeed implies distance. Words like Telegraph and Telephone that use "tele-" are modern inventions but ancient words with a "tele-" prefix are "τηλεβόας" ("televoas", a loudspeaker") and "Tηλέμαχος" (Telemachus, lit. "he who fights from a distance", metaphorically an archer or javelin-thrower; the son of Odysseus).

Edit: many more here->

https://www.greek-language.gr/digitalResources/ancient_greek...

taeric 2 months ago | prev | next |

This reminds me of the equally interesting framing of modern computer failure rates in similar terms to mechanical parts.

This is also a very fun exploration of how many things start mechanical and move to more solid state as they age. I'm curious what major mechanical items are left to move over to solid state? My guess is most things that have changed were instruments in larger things. Gyroscope devices are a fun example.

compiler-devel 2 months ago | prev |

[flagged]

seszett 2 months ago | root | parent | next |

I understand the frustration but I see no reason at all to browser the Internet without ublock these days. I didn't get popups.

compiler-devel 2 months ago | root | parent |

I have nothing against ublock or other programs for ad block. It just seems like we shouldn’t have to participate in the arms race around internet advertising. I would pay for content (like substack) to avoid an experience where I get popups a few seconds apart.