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| Would anyone be capable of making a barcode reader with vacuum tubes? |
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| rstofer:
--- Quote from: T3sl4co1l on November 15, 2021, 10:52:20 pm ---Also, my tube cred, not that anyone doubted :) https://imgur.com/gallery/OF4jAxh Tim --- End quote --- Absolutely outstanding! I remember when Numerical Control systems were based on relay logic. I spent quite a bit of time with a cross-bar PBX system (relay logic done large). |
| rstofer:
--- Quote from: MasterTech on November 15, 2021, 05:16:17 pm --- --- Quote from: rstofer on November 15, 2021, 04:47:28 pm ---I don't see why an engineer today couldn't replicate a system that is still in use, every single day. --- End quote --- That's the thing, replicate. Todays engineers cannot do anything without PCs and microcontrollers and FPGAs and Solidworks.... The amount of work if that had to be done from 0 would be unsurmountable for todays heads. The level of 60s engineers was top-notch. Even the SR71, nothing better has been designed. If all the drawings and tools and calculations done back then were lost for this system, I don't think today graduates would tackle the problem easily. --- End quote --- I think the the ISS and Space Shuttles probably outrank the SR-71. We look back with admiration, realizing that it was designed with slide rules. Today it would be computer simulation. Is it better? Who knows! I sure wouldn't write off today's engineers. There's a fair bit of magic under construction. I'm a huge fan of the F106 - a single engine interceptor only 19 MPH slower than the twin engine F-14. I admire it for the simple reason that my father's fingerprints are all over them - back a long time ago. That, and it was introduced in '59 while the Tomcat came along in '74. The worst decision ever made was to install the MA-1 flight control system which allowed all the mothballed F106s to be used as remote controlled drones. What a waste! They belong in museums! https://www.f-106deltadart.com/flightcontrols.htm The plane could even land without a pilot - the "Cornfield Bomber" - an interesting tale of lore: The old guys were good but I think the newer engineers are better because they know how to use more productive tools. They can also get the wrong answer to significantly more decimal places. |
| Berni:
Bar code scanner is not really a problem with vaccum tubes since all it does is scan a laser across and wait for seeing a particular pattern in the light coming back. So you it just has to detect it, buffer it and then shift it out in serial at a fixed data rate. But when you get to QR codes you basically need a basic vacuum tube computer because the data is encoded with pretty complex error correction codes. Also finding the exact location and orientation of a QR code in a frame of video needs a fair bit of computation that can't be done by just running it trough a bit of logic. Tho if you simplify them down in to requiring the codes to be in a certain orientation and remove the complex encoding then it becomes much like a regular bar code scanner except that you might use a vidicon tube as a camera instead of a laser. Thing is that vaccum tubes can also be made into sort of "integrated circuits" by use of various tricks. So with some clever design you can make a decade counter, shift register, few bits of memory etc... into a single glass tube. They are not just simply FETs with pilot lights. Similar goes for electromechanical computation, there are not just relays that simply turn on and off. Instead its more along the lines of coils moving mechanical systems that can do much smarter things than just an AND gate. This is taken to even more of an advantage in those "analog mechanical computers" used to aim bomb drops, fly planes...etc where gear systems are used to directly calculate a mathematical function in real time, this not only does multiplication trough gear ratios but can produce also addition, subtraction, division, even integration. You still start off with the equation you want to calculate, but there must have been a LOT of manpower involved in designing and building it to turn it into the physical form, taking a team of skilled people months to do. But today the same functionality can be implemented by a single person in a single day using an Arduino. |
| Haenk:
Not that trivial: Barcodes usually use interleaved digit calculations plus checksum. You can do that by a matrix, but this will still require calculations, i.e. creating a computer from scratch. |
| Connecteur:
--- Quote from: Haenk on November 16, 2021, 12:03:35 pm ---Not that trivial: Barcodes usually use interleaved digit calculations plus checksum. You can do that by a matrix, but this will still require calculations, i.e. creating a computer from scratch. --- End quote --- I'm wondering if some genius couldn't come up with circuitry similar to the way TVs used to sync signals using only analog means. |
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