Hey Tim. I just wanted to say, I still come back to watch these videos once every few month to a year. Most people don't realize you miss/forget a LOT from a video just watching it once, you're never gonna retain all of the information in these gems from just one viewing. So I'm still learning stuff from them after about my 4th viewing. And each time makes me wanna make my own lol. If I focused I could probably design and build a digital computer without an CS degree, but I think analog's a bit beyond me. Especially not being too strong in calc. Either way, I wanted to thank you for taking the time to make and share these videos. And for taking the time to address my comment several years ago about the floating inputs. It's nice to see you're willing to give us little folk the time of day. Hehe. Anyways, cheers, buddy. I wish you all the best!
Hello, Mr. Thompson. This video is very insightful. As a programmer from the digital era that did not prioritize mathematics during college, this is eye opening. I should inform you, it seems more people will find your videos soon. This field may become more robust soon. Have a great weekend.
Technically, you still prioritized mathmatics. All computers are just digital math machines. Programming at the end, is just writing mathematical equations in a semi-human language format.
Great video, thank you. I came here because I design and build modular synthesizers and was exploring "soft boolean" functions with transistor logic gates, among other things like sequencers that are under 3-bit address control.
Thank you for watching. I don’t know if you’ve already seen them, but I posted a couple of videos modulating a Moog Mother 32 with the output of the analog computer programmed with the Lorenz equations. Here are links, in case you’d like to watch them: Sounds of Chaos Part 1 - th-cam.com/video/ViDYAYrW9zI/w-d-xo.html, Sounds of Chaos Part 2 - th-cam.com/video/MgAgP0OU6Ho/w-d-xo.html. I’m not much of a musician, but you might get a laugh, and there are some interesting sounds created. I think the analog computer could be a useful tool for augmenting analog synthesis and sound design.
@@timthompson468 in many ways an analogue computer IS simply a very accurate modular synthesizer. I don't know if you like traveling or public speaking but if you ever want to do a talk about analogue computers and their applications at Knobcon (look it up) let me know. I am the curator and would love to have you!
I had a lot of trouble following along due to math being my weakest subject but I was enthralled nonetheless by this demonstration. Thank you for putting this on TH-cam!
Thanks for watching. I find this subject fascinating, but I'm a little weak on the math too. The problem is analog computers are used primarily to solve differential equations, which I consider to be a fairly high level of mathematics. An understanding of calculus is helpful. The key is the problems are typically all about phenomena that change over time - things like the trajectory of a projectile, or a spring-mass system, or radioactive decay. I'm mainly playing around with these to learn more about differential equations and operational amplifiers. I just wish I had more time to spend on it.
You should ideally never leave the inputs or output of an op amp floating, even in a voltage follower configuration with negative feedback like you've done because it will saturate the output and lead to damage or excessive current consumption, and gradual degradation. Texas Instruments has a great application note on properly terminating unused op amps. It's meant for ICs, but I'm sure the theory applies just the same to any op amp, regardless of how it's made. The application note is called How to Properly Configure Unused Operational Amplifiers and the document number is SBOA204A. You can find it easily enough on Google. I'd always been terminating unused op amps wrong for years until I came across this. It may be different with an analog computer, but I thought I would mention it anyways because I would hate to see such a beautiful piece of kit get damaged. Thanks for taking the time to share this with us. It's really great to be able to see an anaolog computer running like this. Cheers.
Nothing\ Thanks for watching. You bring up a very interesting, valid and important point. I am familiar with that TI App Note from a few years ago, and anyone designing with op amps should follow that. What I do now with unused op amps in designs is, space permitting, put in pads for components for “universal” configuration. That way, I can safely disable the op amp if I’m not using it, but the board layout is set up in case later design requirements call for an op amp circuit. I was scratching my head for a while trying to figure out why this did not seem to apply in the analog computers I’ve used. Long story short, it’s because what you see on the front panel is not quite the whole picture. In an analog computer, the op amps are typically set up as inverting amplifiers and shown with single-ended, instead of differential, inputs. Internally the non-inverting input is tied to 0V and the input shown on the front panel is the inverting input. With the output connected to the inverting input, and the non-inverting input connected to 0V, the output is safely configured at 0V, right in the middle of the rails. This is like the safe configuration shown in Fig. 3 of the app note. When programming, I sometimes have the system on with the shorting block out of the feedback path, and an op amp output goes to the rail, as indicated by the front panel overload indicator. This can also occur in normal operation if an equation is not scaled correctly. The overload indicator is mainly a warning that the computational results are invalid. This does not seem to have any adverse impact on the op amps, though, as indicated by the fact that all the GP-6 computers I’ve used have there original op amps installed. I suppose that’s why the app note uses the word “can” instead of “will.” I might dig into this a little more to see if I can understand why the typical, routine overloads don’t seem to cause any harm. Thanks for the input. That is a very useful app note covering an important topic for anyone working with op amps. Op amps led to my interest in analog computers. I don’t have formal education on them, but I’ve learned a lot from the analog computer literature. They early books show how to build discrete op amps. I’ve got a few old Philbrick tube based op amps. I hope to have time to do a video, or possibly a series of videos, on op amps from a historical perspective.
Thanks for the fast and detailed reply. I had a feeling there was more to the op amps than it seemed. I appreciate you clearing that up for me. It's interesting, and reassuring to know that at least with the computers you've used, they all still have their original op amps. It wouldn't be surprising if the designers had some sort of protection in place to protect from damage due to overload considering how easy it would probably be to accidentally scale something wrong. It would be interesting to learn more about how they handled that eventuality. I've never been formally trained in electronics, but much like yourself, learning about op amps has sparked an interest in analog computing, though I'm only just starting down that rabbit hole. I only just got into electronics a couple of years ago, so I'm trying to absorb as much as I can about as many topics as possible. I started learning about how to make a breadboard digital computer, but I got sidetracked when I started learning more about op amps. Something about analog circuits is just so much more appealing to me than digital. Though that's not to say digital isn't interesting in its own right. I have a huge collection of app notes and literature on op amps I still need to digest. I'd love to see you do a video on the philbrick op amps. I first saw them on Mr Carlson's lab and read about them on Ken Shiriff's blog. I found them absolutely fascinating. And I think a historical series on op amps would be a great idea, as well. Thanks again for the fast reply. You've definitely earned yourself another sub. Cheers.
This is way over my head but it's just fascinating. Programming some more complex problem must take a massive amount of effort. It looks like you would be better off with a pen and paper. That is if you don't need a continuous result. Or tweaking a parameter or two without having to recalculate everything again.. Using op-amps for calculation and getting a result in voltage. My mind is blown.
I also find this subject fascinating. You hit on some good points. It could require a huge effort to program a complex problem into an analog computer. I've read of cases where hundreds of operational amplifiers were required to solve problems, requiring weeks to set up the program. Pen and paper would definitely be better for the simple problems I'm demonstrating, but in the pre-1950 era, an analog computer would often be faster than a digital computer, because, once programmed, the solution appears instantly in a graphical format, as opposed to waiting hours or days for a table of numbers. The realtime tweaking of problem parameters was very beneficial, vs. reprogramming and running a digital computer. The analog computer provided more intuitive interaction, too, from what I've read.
@@timthompson468 Actually programming an analog computer isn't harder then a digital computer. Just you have to always bootstrap the whole thing and create a circuit for the problem. Once you have a circuit that solves the problem, an analog computer might just be faster and more realistic then a digital one.
Thanks for watching. I'll try to demonstrate that in a video when I get my EIA TR-10 up and running. It's easier to demonstrate than to describe. The key is to put the oscilloscope in X/Y mode. The computer generates a ramp signal that represents computer time for the x-axis. An equation can be programmed to generate the sine and/or cosine functions. To generate a circle, a sine is used to drive the scope's x-axis, and a cosine is used to drive the y-axis. If the signals are set up correctly, and have the same frequency, a circle is displayed. This is the concept of a phase diagram in mathematics, if I"m not mistaken. Cars and other shapes are difficult. Each line of the drawing must be made with an equation. That requires more resources than I have in my small scale analog computers, but I've seen videos on TH-cam where someone went to the trouble of drawing a car body to demonstrate a suspension simulation.
Thanks. Sorry it took so long to get back to you, but work has been hectic, and I've had to neglect the channel. There are some similarities, especially in the patch bays. I actually have several synthesizers, including a stack of three Moog Mother 32s, that would qualify as modular. I was reading a book on synthesizers and they mentioned an album titled "Processor" where the GP-6 was used to control a series of function generators. It's available on iTunes, so I got a copy. It's a little far out, but it makes some interesting background music. The mixing section of a synthesizer is very similar to the summing amplifier, and a low pass filter could be loosely compared to an integrator. Someday I may try to experiment with using the analog computer with my synthesizers, but I think I'd be hard pressed to do any computations with the synths (lol).
Vsev Krawczeniuk Thanks for the suggestion. Coincidentally, I was just thinking about that yesterday. I’m just an amateur musician, so I’m not sure how to go about that, but I might test out the idea with my Moog Mother 32s. I think the typical analog computer output, a damped sinusoid, would work best as a modulation control voltage, but it might be interesting to hear what it sounds like. I’ve been very busy at work lately, so I haven’t had time to make videos, but I’m taking some time off for Christmas, so I might try to set something up. If the results are worth it, I’ll record a video. Also, thanks for the subscription. I was not sure if the subjects I’m interested in would be interesting to others, but there has been some interest, so I’ll keep at it, when I can find the time.
@@timthompson468 I too would be interested in seeing some interaction between a synthesizer and a computer! I've always thought of analog modular synths as analog computers limited to being comprised only of those elements deemed musical, at the time of their conception in the late 60's. I've sometimes wondered about the possible use of analog computers in musical contexts. I've just found out about your channel anyway, I think I'll take a look at the rest of your videos, and maybe subscribe as well =)
Alaska1925 Thanks for the feedback. I’ve got a lot of irons in the fire, but I managed to record some interesting video over the weekend. I combined a few of my interests and used the GP-6 to solve a Lorenz equation (at the core of chaos theory) and used the outputs of the GP-6 to modulate the Mother-32. The results were very interesting, but not necessarily musical, at least not in the traditional sense. I’ll try to edit the video and have it up by next week, if my job doesn’t get in the way. This first video will just be a knob-twiddling demonstration, so to speak, but I will try to put together a detailed video later showing all the ins and outs. Due to the nature and frequency of the analog computer signals, they are either too fast or too slow to provide musical modulation, but, in the raw form, I think the signals are great for abstract sound design. I have an idea for a way to modify the GP-6 so the signals are more appropriate for synthesizer modulation. Feel free to subscribe. You might just put me into triple digits.
Why do you (at about 8:18) invert the output of the wiper arm from pot. 2 twice before display? Is it because you can only display the outputs of amplifiers or is there another reason?
Martin Koch Correct. In operation, only the op amp outputs are available, but I wanted access to this input from the potentiometer. I invert it twice because all amplifiers invert, but I wanted the '"true" signal. Normally this would be a waste of resources, but the amplifiers were available, so it was acceptable for this demonstration.
Very interesting, Tim! Thanks for posting it. In contrast to most folks, it seems, I find digital computing far harder to comprehend, conceptually, than i do analog computation. You should look into the gun director tables in naval ships, I think you'd find them interesting, as purely mechanical versions of your Comdyna. (dreadnoughtproject.org/tfs/index.php/Dreyer_Fire_Control_Table)
Thanks. Sorry it took so long to get back to you, but work has been hectic lately, and I've had to neglect this channel. I have seen those mechanical gun director computers in TH-cam videos. I think it was on the Jeff Quitney channel. I've seen a training video that shows how the integrators work, and another video that has a demonstration of the operation. I think it took a crew of about five seamen to man the thing. It was fascinating. They each seemed to be focused on one section of the computer.
Meanwhile I can't wrap my head around these wonderfully nuanced electronic thought machines, because I've grown up with digital electronics everywhere. I can design complex logic circuits literally while half asleep but I can't ever wrap my head around analog computing, I am literally about to become an electrician just to break out of that digital box of thought.
Shay XT, first of all, thanks for watching. I wouldn’t say the math is required, but it helps. Analog computers are fundamentally differential equation solvers. It’s not necessary to fully understand DEs in order to use an analog computer, but most analog computer literature references DEs, so it helps to fully understand the notation. The first chapter or two of a good book on DEs would likely cover that. DEs are an outgrowth of calculus, so knowing a bit about calculus goes a long way. I’m not a math expert by any means; in fact, I became interested in analog computers as a way to learn more about DEs. A good, relatively inexpensive book I’ve added to my library is “Analog Computer Programming” by Bernd Ulmann. There are a lot of books available on the subject, but the older ones can be expensive. The books by Korn and Korn are classics and sometimes can be found for under $25 on eBay.
@@timthompson468 Thank you for your reply, and I am glad I saw this. The reason I ask is for a type of application I have been thinking about, which has so far been implemented by engineers using digital logic, however my gut feeling has been inclining more towards an analog implementation. I am also a musician so a lot of this goes within my radar of understanding, save the analytical aspect. I will check for those books, and delve more into the calculus requirements. Linear Algebra is a beauty though :)...just saying.
@@timthompson468 Hey Tim, I'm teaching myself electrical engineering and analog computational theory. I needed some math and was working on dif calc until I realized I couldn't learn it without help. I got a math tutor but they told me they aren't experts in differential calc - but that "I shouldn't need all of dif calc for designing/programming analog computers". Although my tutor's education isn't directly related he is a double major in robotics and machine learning from CMU - so he *does* know more than me. Would you say it is accurate that I mostly just need differential equations? Have you found that you need more than just ODEs for working with analog computers?
EuphoricDan First of all, thanks for watching. It’s a little complicated, but I would not disagree with your tutor. From what I’ve seen, calculus is usually broken up into three one-semester courses. It would be hard to learn differential equations without the first semester of calculus (meaning about the first one-third of a typical calculus text book). I see differential equations as an extension of calculus. All the equations you’ll find in a book on DE’s use the symbols defined in Calc I, so it’s a prerequisite, but you don’t necessarily need the material from Calc II and III. Since analog computers are primarily tools for solving DEs, you need to have familiarity with DEs to understand the literature covering analog computers. That being said, the more math you have under your belt the more electronics and analog computers will make sense, so I’d encourage you to learn as much as you can. There are a lot of great resources on TH-cam for learning math. Kahn Academy comes to mind, but there are a ton of others. Be sure you have the prerequisites for calculus. You need to know algebra since all calculus expressions are really just shorthand for a lot of algebra in my view. Trigonometry and Pre-Calculus are also important. It always amazes me how often the right triangle is used to solve problems in a wide variety of subjects. I hope that helps. Good luck with your self-education.
@@timthompson468 Thank you so much for your reply! Any text books that you'd recommend for the calculus? I do better with a physical book most of the time. My end goal here is to incorporate dynamic analog processing into Neural Networks. I've got a few years of work here ;) I just received some Field Programmable Analog Arrays to play around with but it'll be a year or more until I can start to use them properly. They are dynamically reprogrammable so they can self-adapt to change what they are doing as necessary (as opposed to your machine that you have to physically reprogram for each equation). Fucking incredible tech man, blows my mind.
Pedro Couto I don’t want to make any promises I can’t keep, but I’ll try. I’ve seen that in some of the literature, but it typically requires more than the four integrators available in the GP-6. I’ve got more than one GP-6, and the manual indicates I can connect multiple units to solve higher-order equations. I’d like to try that and the automobile suspension problems might be a good test case. Right now, my job is taking a lot of my time, so it might be a while, but I’ll put that on the list. Thank you for watching and for the suggestion.
Why did you use an acceleration of -0.161? Your scale factor will be 200ft/V. Using -0.322 V (32.2 ft/s^2) is much more convenient because your scale factor (100ft/V) can be applied by just shifting the decimal point two places. You will have to multiply the output voltage by a factor of 200 to get back to feet again. The time-base scales by a factor of 400. (1 time constant "analog computer time" = 2.5ms real time) Do you know how well the precision resistors (50k) and capacitors (50nF) have aged? Are there trim pots and caps inside that allow for readjustment or "calibration" ?
Thanks. That's a good point on the scale factor. It's been a while since I made this video, but I think the rationale was to scale the voltages to take advantage of as much of the oscilloscope display as possible, and stay out of the noise. The texts recommend that to stay out of the noise as much as possible, but I think your idea of keeping the conversion math simple is valid. From what I've seen so far, the calibration is close. In the few experiments I've done, the results are as expected. Each amplifier has a series of calibration resistors, but I've yet to calibrate any of my GP-6s. The caps are very high quality. As I recall, they're 20uF (to make a TC of 1s with the 50k resistors). They're still available from Electrocube, but they cost about $350, and the price doesn't drop much in quantity. I think that's part of the reason no one makes analog computers anymore.
$350 per capacitor? Ouch! I've never had the opportunity to use one, but I still think these analog computers are cool. Thanks for the interesting videos.
There is a gentleman by the name of Bernd Ulmann in Germany who I believe is trying to build new production analog computers, but the information is spotty. He has a TH-cam channel and also works with vintage analog computers, I think the new production models are for educational purposes, and could be expensive. I think the best option is to purchase vintage models but they don’t show up on eBay as much as they used to. Also, you must be very careful to ensure that all the parts are there. I’ve had to get refunds in the past on units that were sold as working, but were gutted. Making your own is an option, but I think that would also be expensive. The manual for the Comdyna GP-6 is available online and has all the schematics. The most expensive part is the integrating capacitor. The ones used in the Comdyna GP-6 sell for over $300 each new. Less expensive caps could probably be used, but it would be a trade off between price and performance. Sorry I don’t have a better answer, but it is complicated. The texts written by Korn and Korn describe how to build tube and transistor based analog computers, but it would be easier using modern op amps. Good luck, and thanks for watching.
LonewolfeSlayer, Sure, and thanks for watching. From the top, 1. Analog Computer Simulation of Engineering Systems, James, Smith and Wolford, ISBN 0-7002-2376-2 2. Ordinary Differential Equations, Tenenbaum and Pollard, ISBN 978-0-486-64940-5 3. Methods for Solving Engineering Problems Using Analog Computers, Levine, LoCCN 63-1794 4. Analog Computer Programming, Rekoff, LoCCN 67-22999 5. Design Fundamentals of Analog Computer Components, Howe, LoCCN 61-8536 6. Basics of Analog Computers, Truitt and Rogers, LoCCN 60-10469 7. Analog Computer Techniques, Johnson, LoCCN 63-16196 8. Electronic Analog and Hybrid Computers, Korn and Korn, LoCCN 63-23389 9. Differential Equations and Linear Algebra, Strang, ISBN 978-0-9802327-9-0 10. A First Course in Differential Equations, Zill, ISBN 0-534-41878-3 11. Calculus, Larson, Hostetler and Edwards, ISBN 0-618-14180-4 Some of these predate the ISBN system, so I list the Library of Congress Catalog Number. I purchased most of these on eBay. The two “classics” of analog computing are 7, by Johnson, and 8, by Korn and Korn. 6, by Truitt and Rogers is very interesting and relatively easy to read. It was written by two engineers from EAI, an analog computer manufacturer. I hope this helps.
Not specifically. In the literature I've read, pneumatic and hydraulic analog computers were mentioned briefly, but only electronic computers were covered in depth. I just finished "Analogue Computers" by K. N. Dodd, where the last chapter covered "Fluidics." That was a fascinating topic. There were pneumatic computers invented that included amplifiers, resistors, and integrators for the analog side, and digital logic gates and flip-flops on the digital side, all based on compressed air. They could be manufactured using printed circuit techniques. Apparently, their advantage is they weren't as susceptible to shock, vibration, temperature or radiation as electronics. I've run across a Foxboro pneumatic analog computer on eBay from time to time, but I have no way to apply it, since my background is in electronics.
This says Remington Rand was into this and the links at the bottoms show that it was giving some thought by lots of smart guys. www.google.com/patents/US3190554 I have asked around to see if N.A.S.A was ever into this but so far nada. Bet this would make a cool 3D printing project for some Tech High School kids. If Babbage had this tech he could have had the pipe organ folks build his engine for him and Lady Lovelace could have invented COBOL . ( I think that is kinda funny so I post it when I can) Dig the old kit "computer" Geniac . The guy who posted it calls it "A story in digital. " Now on to see if anybody has posted something on Collision Based Computing using Bristle Bots.
Mohan Besetty, a book I like is Elementary Electricity and Electronics Component by Component, by Mannie Horowitz, ISBN 0-8306-0853-2. It is at the basic technician level and does not require a lot of math background. It can be found on eBay for less than $10. Another great book is The Art of Electronics, by Paul Horowitz and Winfield Hill, ISBN 9780521370950. This book is more expensive, but I’ve seen the second edition on eBay for less than $50. The third edition might be better, but I think the second edition is very good. I have the Kindle version. Another very useful resource you might want is MicroCap SPICE simulation software. It is available for free here: spectrum-soft.com/download/download.shtm. This is a very good professional tool for simulating circuits. It includes an extensive reference manual and many example circuits. I use it every day and find it very useful for both learning and for designing new circuits. Good luck.
Hello sir thanku for replying i was interested and fascinated in analog electronics escp in op amp i want to extend my knowledge can you suggest me a book i was undergrade first year student
I have purchased many op amp books over the years, but I have two favorite books that I recommend. First, an older book, Operational Amplifiers Theory and Practice, by James K. Roberge. Mr. Roberge was a professor at MIT, and they posted a video course he made in the 1985 called Electronic Feedback Systems, covering operational amplifiers. Here’s a link to the MIT videos: th-cam.com/play/PLUl4u3cNGP62in17jH_DiJMkCGNM6Xni-.html The second book is Design with Operational Amplifiers and Analog Integrated Circuits, by Sergio Franco. I have the third edition which is a little old, published in 2002. This book is very good. It covers op amp basics and many application circuits. The book by Franco is listed on eBay for less than $10 in the US (some people charge much more, so be sure to sort by price if you go that route). The book by Roberge is more expensive. I find it interesting for historical context, but if you have to choose one, I’d recommend the Franco book. I hope this helps. Good luck.
Sorry it took me a while to get to this. You are correct. In fact analog computer operation is nearly instantaneous, in that the output of the op amp starts as soon as the computer is set to operate. Technically, the op amps all work in parallel, so the final output is instantaneous as well. Digital computers must perform operations serially, for the most part, so, at least in operation, the analog computer has s speed advantage. I think the reason they fell out of favor, though, is partly due to the time and care required to program an analog computer. Some of the problems in aeronautics required patching hundreds of op amps, and associated potentiometers and function generators. When the time taken to program them, and "debug" the program, digital computers eventually gained an advantage, especially when higher level programming languages became available. I've seen articles on the web about using analog computing methods for some functions in modern computers, now that Moore's Law is petering out, but I'm not sure if anything will come of it. That's interesting, but a bit beyond my scope.
Mohan Besetty, I taught myself linear circuit analysis by reading a book, so I am not familiar with any videos on the subject. If you search on TH-cam, there are quite a few videos on the subject. You might try viewing a few of them to see if you like one. Here is one I took a quick look at that seems pretty good: th-cam.com/video/sqxzQkAdJm0/w-d-xo.html. The Kahn academy has videos on the subject, and I think they do good videos. If you’re interested, the book I used to learn circuit analysis (recommended to me by a former boss), is Circuit Analysis, Allan D. Kraus, ISBN 0-314-79500-6.This book requires some knowledge of calculus, but it teaches you circuit analysis with differential equations and the Laplace transform. Another book that was recommended to me is Circuit Analysis, Irving L. Kosow, ISBN 0-471-03067-8. I have not read the Kosow book yet, but it has limited calculus topics that I can find in it. I purchased both of these books on eBay in the past five years, but I could not find either of them listed there or on Amazon today. Good luck.
so to me this seems like a fancy kind of calculator. not really a general purpose "computer" as we would think of them... so you would not be able to make a "hello world" program with this. or a game. it's just used to solve certain kinds of mathematical problems - yes?
Thanks for watching. You are, for the most part, correct. The analog computer predates digital computers, and it was used primarily to quickly solve differential equations. Another name fo the analog computer was differential analyzer. The were also used to simulate control systems. It was much faster, though less precise, than the early digital computers, but it is very different in operation and application. The earliest digital computers measured their speed in seconds per operation instead of operations per second, so it was impractical to use them in solving differential equations using numerical methods. The output of the analog computer is a plot of the output of the solution to the differential equation, whereas in modern digital computers, the solution is the equation itself. In analog computers there is still a distinction between general purpose and special purpose. The GP-6 is considered a general purpose computer because it can be programmed for a variety of applications. In the Apollo era, NASA had an analog computer based lunar lander simulator which would be an example of a special purpose analog computer. With resources and clever programming, a reasonable graphics display can be made, but that’s beyond my capabilities. There is a video on TH-cam of a car suspension simulation that displays a simple car model driving down a road with simulated bumps. That’s very impressive considering the technology, but it’s nothing like what a modern gaming computer could do.
are you still around, can you reply to this if youre able to help me with a problem starting in analog, i have all the eqp. i beginning to suspect my computer is malfunctioning
First, thanks for watching. I am still around, and I might be able to help, if the problem isn't too complex. I'm trying to get back into making videos; I can't believe it's been four years since I posted one. Time flies. Let me know what your issue is, and what equipment you're using.
Yes, but it would not be easy. If you search for “Comdyna GP-6 Manual” you can find the pdf of the manual for the one I use which includes schematics and wiring diagrams. You could feasibly adapt that for modern components. The hard part is you would need very good, low-leakage capacitors, a lot of multi-segment wafer switches and several 10-turn potentiometers. These components are very expensive, especially if you use the ones found in the GP-6. It’s possible to improvise but the results might not be as good. If I were to try it, I would also use less expensive interconnect components than the banana jacks on the interface panels of the GP-6. The system is modular, so it’s possible to start with one op amp/integrator, get that circuit working and then copy that to make as many integrators as is required.
WOW!! Could these analog computers from the 50's and 60's multiply/divide numbers? I mean, digital computers can't compute really well things like 10*0.1....
Thanks for watching. There were functions to multiply and divide, through various means. In some cases they would use a servo motor, but later an electronic multiplier was developed. The GP-6 has an electronic multiplier. I don’t remember off the top of my head what the IC was, but it was commonly used in the 70s. The multiplier can be used in reverse to perform division. If you look at my videos titled “Sounds of Chaos” I use the GP-6 multiplier there to program the Lorenz equation. I’m using it to modulate a Moog synthesizer, but you can see the chaotic Lorenz equation plotted on the oscilloscope. Thanks again.
Thanks for the suggestion. Sorry it took so long to get back to you, but work has been hectic, and I've had to neglect the channel. I agree. I tried showing a wiring diagram from the manual in some of the videos, but that is hard to follow too. I'll try making symbols based on the analog computer texts in LTSpice to show the schematic of the analog computer solution in future videos. There might not be enough real estate to show them side-by-side, but I can do an overlay when explaining the circuit.
Eric Johnson, the units I’ve purchased on eBay did not come with instructions, but if you search for “Comdyna GP-6” you will easily find pdf versions of the original manual. The manual is relatively short, but has complete operating instructions as well as schematics of all the circuits. The only issue is that, although the GP-6 evolved substantially over the years, I’ve only seen one version of the manual online, so the schematics in the manual might not match a particular unit that is purchased today. The operating instructions don’t change at all over the various units that have the digital meter display, so for the purpose of operation, the manual will work for any such unit. The manual is also a good source for learning the basic operation of any analog computer. I hope that helps, and thanks for watching.
![จังหวะนี้ - เม้ก อภิสิทธิ์ [ Official MV ] จอนนี่มิวสิค](http://i.ytimg.com/vi/4gQRZCkRyiU/mqdefault.jpg)
I never thought that I would ever see this on you-tube; amazing! Great job and please keep it up
Thanks. More to come, but I've been busy with work lately.
Hey Tim. I just wanted to say, I still come back to watch these videos once every few month to a year. Most people don't realize you miss/forget a LOT from a video just watching it once, you're never gonna retain all of the information in these gems from just one viewing. So I'm still learning stuff from them after about my 4th viewing. And each time makes me wanna make my own lol. If I focused I could probably design and build a digital computer without an CS degree, but I think analog's a bit beyond me. Especially not being too strong in calc. Either way, I wanted to thank you for taking the time to make and share these videos. And for taking the time to address my comment several years ago about the floating inputs. It's nice to see you're willing to give us little folk the time of day. Hehe. Anyways, cheers, buddy. I wish you all the best!
Hello, Mr. Thompson. This video is very insightful. As a programmer from the digital era that did not prioritize mathematics during college, this is eye opening.
I should inform you, it seems more people will find your videos soon. This field may become more robust soon. Have a great weekend.
Technically, you still prioritized mathmatics. All computers are just digital math machines. Programming at the end, is just writing mathematical equations in a semi-human language format.
@@paxtoncargill4661not really.
Great video, thank you. I came here because I design and build modular synthesizers and was exploring "soft boolean" functions with transistor logic gates, among other things like sequencers that are under 3-bit address control.
Thank you for watching. I don’t know if you’ve already seen them, but I posted a couple of videos modulating a Moog Mother 32 with the output of the analog computer programmed with the Lorenz equations. Here are links, in case you’d like to watch them: Sounds of Chaos Part 1 - th-cam.com/video/ViDYAYrW9zI/w-d-xo.html, Sounds of Chaos Part 2 - th-cam.com/video/MgAgP0OU6Ho/w-d-xo.html. I’m not much of a musician, but you might get a laugh, and there are some interesting sounds created. I think the analog computer could be a useful tool for augmenting analog synthesis and sound design.
@@timthompson468 in many ways an analogue computer IS simply a very accurate modular synthesizer. I don't know if you like traveling or public speaking but if you ever want to do a talk about analogue computers and their applications at Knobcon (look it up) let me know. I am the curator and would love to have you!
I had a lot of trouble following along due to math being my weakest subject but I was enthralled nonetheless by this demonstration. Thank you for putting this on TH-cam!
Thanks for watching. I find this subject fascinating, but I'm a little weak on the math too. The problem is analog computers are used primarily to solve differential equations, which I consider to be a fairly high level of mathematics. An understanding of calculus is helpful. The key is the problems are typically all about phenomena that change over time - things like the trajectory of a projectile, or a spring-mass system, or radioactive decay. I'm mainly playing around with these to learn more about differential equations and operational amplifiers. I just wish I had more time to spend on it.
amazing stuff! I need one now!
This reminds me of when I was in grade 6 I made an analog multiplier/divider out of 2 potentiometers and a meter. Good times!
You should ideally never leave the inputs or output of an op amp floating, even in a voltage follower configuration with negative feedback like you've done because it will saturate the output and lead to damage or excessive current consumption, and gradual degradation.
Texas Instruments has a great application note on properly terminating unused op amps. It's meant for ICs, but I'm sure the theory applies just the same to any op amp, regardless of how it's made. The application note is called How to Properly Configure Unused Operational Amplifiers and the document number is SBOA204A. You can find it easily enough on Google. I'd always been terminating unused op amps wrong for years until I came across this.
It may be different with an analog computer, but I thought I would mention it anyways because I would hate to see such a beautiful piece of kit get damaged. Thanks for taking the time to share this with us. It's really great to be able to see an anaolog computer running like this. Cheers.
Nothing\ Thanks for watching. You bring up a very interesting, valid and important point. I am familiar with that TI App Note from a few years ago, and anyone designing with op amps should follow that. What I do now with unused op amps in designs is, space permitting, put in pads for components for “universal” configuration. That way, I can safely disable the op amp if I’m not using it, but the board layout is set up in case later design requirements call for an op amp circuit.
I was scratching my head for a while trying to figure out why this did not seem to apply in the analog computers I’ve used. Long story short, it’s because what you see on the front panel is not quite the whole picture. In an analog computer, the op amps are typically set up as inverting amplifiers and shown with single-ended, instead of differential, inputs. Internally the non-inverting input is tied to 0V and the input shown on the front panel is the inverting input. With the output connected to the inverting input, and the non-inverting input connected to 0V, the output is safely configured at 0V, right in the middle of the rails. This is like the safe configuration shown in Fig. 3 of the app note.
When programming, I sometimes have the system on with the shorting block out of the feedback path, and an op amp output goes to the rail, as indicated by the front panel overload indicator. This can also occur in normal operation if an equation is not scaled correctly. The overload indicator is mainly a warning that the computational results are invalid. This does not seem to have any adverse impact on the op amps, though, as indicated by the fact that all the GP-6 computers I’ve used have there original op amps installed. I suppose that’s why the app note uses the word “can” instead of “will.” I might dig into this a little more to see if I can understand why the typical, routine overloads don’t seem to cause any harm.
Thanks for the input. That is a very useful app note covering an important topic for anyone working with op amps. Op amps led to my interest in analog computers. I don’t have formal education on them, but I’ve learned a lot from the analog computer literature. They early books show how to build discrete op amps. I’ve got a few old Philbrick tube based op amps. I hope to have time to do a video, or possibly a series of videos, on op amps from a historical perspective.
Thanks for the fast and detailed reply. I had a feeling there was more to the op amps than it seemed. I appreciate you clearing that up for me. It's interesting, and reassuring to know that at least with the computers you've used, they all still have their original op amps. It wouldn't be surprising if the designers had some sort of protection in place to protect from damage due to overload considering how easy it would probably be to accidentally scale something wrong. It would be interesting to learn more about how they handled that eventuality.
I've never been formally trained in electronics, but much like yourself, learning about op amps has sparked an interest in analog computing, though I'm only just starting down that rabbit hole. I only just got into electronics a couple of years ago, so I'm trying to absorb as much as I can about as many topics as possible. I started learning about how to make a breadboard digital computer, but I got sidetracked when I started learning more about op amps. Something about analog circuits is just so much more appealing to me than digital. Though that's not to say digital isn't interesting in its own right. I have a huge collection of app notes and literature on op amps I still need to digest.
I'd love to see you do a video on the philbrick op amps. I first saw them on Mr Carlson's lab and read about them on Ken Shiriff's blog. I found them absolutely fascinating. And I think a historical series on op amps would be a great idea, as well.
Thanks again for the fast reply. You've definitely earned yourself another sub. Cheers.
This is way over my head but it's just fascinating. Programming some more complex problem must take a massive amount of effort. It looks like you would be better off with a pen and paper. That is if you don't need a continuous result. Or tweaking a parameter or two without having to recalculate everything again.. Using op-amps for calculation and getting a result in voltage. My mind is blown.
I also find this subject fascinating. You hit on some good points. It could require a huge effort to program a complex problem into an analog computer. I've read of cases where hundreds of operational amplifiers were required to solve problems, requiring weeks to set up the program. Pen and paper would definitely be better for the simple problems I'm demonstrating, but in the pre-1950 era, an analog computer would often be faster than a digital computer, because, once programmed, the solution appears instantly in a graphical format, as opposed to waiting hours or days for a table of numbers. The realtime tweaking of problem parameters was very beneficial, vs. reprogramming and running a digital computer. The analog computer provided more intuitive interaction, too, from what I've read.
@@timthompson468 Actually programming an analog computer isn't harder then a digital computer. Just you have to always bootstrap the whole thing and create a circuit for the problem. Once you have a circuit that solves the problem, an analog computer might just be faster and more realistic then a digital one.
I wonder if the fetch-decode-execute-write back paradigm of current processors can be applied to this. An analog co-processor to digital processors.
It seems like it wouldn't be too difficult to build one one of these from a bunch of op amps, pots, and such.
that looks very flexible so It would have some complexity about it
I would like to see how you program graphics on an analog computer. How do you draw circles and sinus waves, cars and so on.
Thanks for watching. I'll try to demonstrate that in a video when I get my EIA TR-10 up and running. It's easier to demonstrate than to describe. The key is to put the oscilloscope in X/Y mode. The computer generates a ramp signal that represents computer time for the x-axis. An equation can be programmed to generate the sine and/or cosine functions. To generate a circle, a sine is used to drive the scope's x-axis, and a cosine is used to drive the y-axis. If the signals are set up correctly, and have the same frequency, a circle is displayed. This is the concept of a phase diagram in mathematics, if I"m not mistaken. Cars and other shapes are difficult. Each line of the drawing must be made with an equation. That requires more resources than I have in my small scale analog computers, but I've seen videos on TH-cam where someone went to the trouble of drawing a car body to demonstrate a suspension simulation.
Kinda lika modular synthesizers (which are, in some sense, analog computers)
Thanks. Sorry it took so long to get back to you, but work has been hectic, and I've had to neglect the channel. There are some similarities, especially in the patch bays. I actually have several synthesizers, including a stack of three Moog Mother 32s, that would qualify as modular.
I was reading a book on synthesizers and they mentioned an album titled "Processor" where the GP-6 was used to control a series of function generators. It's available on iTunes, so I got a copy. It's a little far out, but it makes some interesting background music.
The mixing section of a synthesizer is very similar to the summing amplifier, and a low pass filter could be loosely compared to an integrator. Someday I may try to experiment with using the analog computer with my synthesizers, but I think I'd be hard pressed to do any computations with the synths (lol).
@@timthompson468 I would be very interested to see the computer used with the synthesizer. Subscribed, just in case you do it.
Vsev Krawczeniuk Thanks for the suggestion. Coincidentally, I was just thinking about that yesterday. I’m just an amateur musician, so I’m not sure how to go about that, but I might test out the idea with my Moog Mother 32s. I think the typical analog computer output, a damped sinusoid, would work best as a modulation control voltage, but it might be interesting to hear what it sounds like. I’ve been very busy at work lately, so I haven’t had time to make videos, but I’m taking some time off for Christmas, so I might try to set something up. If the results are worth it, I’ll record a video. Also, thanks for the subscription. I was not sure if the subjects I’m interested in would be interesting to others, but there has been some interest, so I’ll keep at it, when I can find the time.
@@timthompson468 I too would be interested in seeing some interaction between a synthesizer and a computer! I've always thought of analog modular synths as analog computers limited to being comprised only of those elements deemed musical, at the time of their conception in the late 60's.
I've sometimes wondered about the possible use of analog computers in musical contexts. I've just found out about your channel anyway, I think I'll take a look at the rest of your videos, and maybe subscribe as well =)
Alaska1925 Thanks for the feedback. I’ve got a lot of irons in the fire, but I managed to record some interesting video over the weekend. I combined a few of my interests and used the GP-6 to solve a Lorenz equation (at the core of chaos theory) and used the outputs of the GP-6 to modulate the Mother-32. The results were very interesting, but not necessarily musical, at least not in the traditional sense. I’ll try to edit the video and have it up by next week, if my job doesn’t get in the way. This first video will just be a knob-twiddling demonstration, so to speak, but I will try to put together a detailed video later showing all the ins and outs. Due to the nature and frequency of the analog computer signals, they are either too fast or too slow to provide musical modulation, but, in the raw form, I think the signals are great for abstract sound design. I have an idea for a way to modify the GP-6 so the signals are more appropriate for synthesizer modulation. Feel free to subscribe. You might just put me into triple digits.
Why do you (at about 8:18) invert the output of the wiper arm from pot. 2 twice before display? Is it because you can only display the outputs of amplifiers or is there another reason?
Martin Koch Correct. In operation, only the op amp outputs are available, but I wanted access to this input from the potentiometer. I invert it twice because all amplifiers invert, but I wanted the '"true" signal. Normally this would be a waste of resources, but the amplifiers were available, so it was acceptable for this demonstration.
Very interesting, Tim! Thanks for posting it. In contrast to most folks, it seems, I find digital computing far harder to comprehend, conceptually, than i do analog computation. You should look into the gun director tables in naval ships, I think you'd find them interesting, as purely mechanical versions of your Comdyna. (dreadnoughtproject.org/tfs/index.php/Dreyer_Fire_Control_Table)
Thanks. Sorry it took so long to get back to you, but work has been hectic lately, and I've had to neglect this channel. I have seen those mechanical gun director computers in TH-cam videos. I think it was on the Jeff Quitney channel. I've seen a training video that shows how the integrators work, and another video that has a demonstration of the operation. I think it took a crew of about five seamen to man the thing. It was fascinating. They each seemed to be focused on one section of the computer.
Meanwhile I can't wrap my head around these wonderfully nuanced electronic thought machines, because I've grown up with digital electronics everywhere. I can design complex logic circuits literally while half asleep but I can't ever wrap my head around analog computing, I am literally about to become an electrician just to break out of that digital box of thought.
Are the operational amplifiers made form discrete transistors, or are they integrated circuits?
The Comdyna GP-6 uses the 741 op amp integrated circuit. I recently picked up two EAI TR-10 and TR-20 computers. Those use discrete transistors.
Hi there Tim, thanks for this. Do the books on the table suggest the math material required to understand analog computing?
Shay XT, first of all, thanks for watching. I wouldn’t say the math is required, but it helps. Analog computers are fundamentally differential equation solvers. It’s not necessary to fully understand DEs in order to use an analog computer, but most analog computer literature references DEs, so it helps to fully understand the notation. The first chapter or two of a good book on DEs would likely cover that. DEs are an outgrowth of calculus, so knowing a bit about calculus goes a long way. I’m not a math expert by any means; in fact, I became interested in analog computers as a way to learn more about DEs. A good, relatively inexpensive book I’ve added to my library is “Analog Computer Programming” by Bernd Ulmann. There are a lot of books available on the subject, but the older ones can be expensive. The books by Korn and Korn are classics and sometimes can be found for under $25 on eBay.
@@timthompson468 Thank you for your reply, and I am glad I saw this. The reason I ask is for a type of application I have been thinking about, which has so far been implemented by engineers using digital logic, however my gut feeling has been inclining more towards an analog implementation. I am also a musician so a lot of this goes within my radar of understanding, save the analytical aspect. I will check for those books, and delve more into the calculus requirements. Linear Algebra is a beauty though :)...just saying.
@@timthompson468 Hey Tim, I'm teaching myself electrical engineering and analog computational theory. I needed some math and was working on dif calc until I realized I couldn't learn it without help. I got a math tutor but they told me they aren't experts in differential calc - but that "I shouldn't need all of dif calc for designing/programming analog computers". Although my tutor's education isn't directly related he is a double major in robotics and machine learning from CMU - so he *does* know more than me.
Would you say it is accurate that I mostly just need differential equations? Have you found that you need more than just ODEs for working with analog computers?
EuphoricDan First of all, thanks for watching. It’s a little complicated, but I would not disagree with your tutor. From what I’ve seen, calculus is usually broken up into three one-semester courses. It would be hard to learn differential equations without the first semester of calculus (meaning about the first one-third of a typical calculus text book). I see differential equations as an extension of calculus. All the equations you’ll find in a book on DE’s use the symbols defined in Calc I, so it’s a prerequisite, but you don’t necessarily need the material from Calc II and III. Since analog computers are primarily tools for solving DEs, you need to have familiarity with DEs to understand the literature covering analog computers. That being said, the more math you have under your belt the more electronics and analog computers will make sense, so I’d encourage you to learn as much as you can. There are a lot of great resources on TH-cam for learning math. Kahn Academy comes to mind, but there are a ton of others. Be sure you have the prerequisites for calculus. You need to know algebra since all calculus expressions are really just shorthand for a lot of algebra in my view. Trigonometry and Pre-Calculus are also important. It always amazes me how often the right triangle is used to solve problems in a wide variety of subjects. I hope that helps. Good luck with your self-education.
@@timthompson468 Thank you so much for your reply! Any text books that you'd recommend for the calculus? I do better with a physical book most of the time.
My end goal here is to incorporate dynamic analog processing into Neural Networks. I've got a few years of work here ;) I just received some Field Programmable Analog Arrays to play around with but it'll be a year or more until I can start to use them properly. They are dynamically reprogrammable so they can self-adapt to change what they are doing as necessary (as opposed to your machine that you have to physically reprogram for each equation). Fucking incredible tech man, blows my mind.
Analog Neural Networks have been shown to recognize text up to 96% certainty.
can you give examples of it being used for suspension design?
Pedro Couto I don’t want to make any promises I can’t keep, but I’ll try. I’ve seen that in some of the literature, but it typically requires more than the four integrators available in the GP-6. I’ve got more than one GP-6, and the manual indicates I can connect multiple units to solve higher-order equations. I’d like to try that and the automobile suspension problems might be a good test case. Right now, my job is taking a lot of my time, so it might be a while, but I’ll put that on the list. Thank you for watching and for the suggestion.
Why did you use an acceleration of -0.161? Your scale factor will be 200ft/V. Using -0.322 V (32.2 ft/s^2) is much more convenient because your scale factor (100ft/V) can be applied by just shifting the decimal point two places.
You will have to multiply the output voltage by a factor of 200 to get back to feet again. The time-base scales by a factor of 400. (1 time constant "analog computer time" = 2.5ms real time)
Do you know how well the precision resistors (50k) and capacitors (50nF) have aged? Are there trim pots and caps inside that allow for readjustment or "calibration" ?
Thanks. That's a good point on the scale factor. It's been a while since I made this video, but I think the rationale was to scale the voltages to take advantage of as much of the oscilloscope display as possible, and stay out of the noise. The texts recommend that to stay out of the noise as much as possible, but I think your idea of keeping the conversion math simple is valid.
From what I've seen so far, the calibration is close. In the few experiments I've done, the results are as expected. Each amplifier has a series of calibration resistors, but I've yet to calibrate any of my GP-6s. The caps are very high quality. As I recall, they're 20uF (to make a TC of 1s with the 50k resistors). They're still available from Electrocube, but they cost about $350, and the price doesn't drop much in quantity. I think that's part of the reason no one makes analog computers anymore.
$350 per capacitor? Ouch! I've never had the opportunity to use one, but I still think these analog computers are cool. Thanks for the interesting videos.
I'd like to get my hands on an analog computer. Are there new ones out there, or does one have to build one?
There is a gentleman by the name of Bernd Ulmann in Germany who I believe is trying to build new production analog computers, but the information is spotty. He has a TH-cam channel and also works with vintage analog computers, I think the new production models are for educational purposes, and could be expensive. I think the best option is to purchase vintage models but they don’t show up on eBay as much as they used to. Also, you must be very careful to ensure that all the parts are there. I’ve had to get refunds in the past on units that were sold as working, but were gutted. Making your own is an option, but I think that would also be expensive. The manual for the Comdyna GP-6 is available online and has all the schematics. The most expensive part is the integrating capacitor. The ones used in the Comdyna GP-6 sell for over $300 each new. Less expensive caps could probably be used, but it would be a trade off between price and performance. Sorry I don’t have a better answer, but it is complicated. The texts written by Korn and Korn describe how to build tube and transistor based analog computers, but it would be easier using modern op amps. Good luck, and thanks for watching.
As a follow up, the company I’m referring to in my previous reply is Analog Paradigm. They have a website, but I did not look to deeply into it.
@@timthompson468 thank you. This is very helpful.
Is there a way you can list all the books in the background?
LonewolfeSlayer, Sure, and thanks for watching.
From the top,
1. Analog Computer Simulation of Engineering Systems, James, Smith and Wolford, ISBN 0-7002-2376-2
2. Ordinary Differential Equations, Tenenbaum and Pollard, ISBN 978-0-486-64940-5
3. Methods for Solving Engineering Problems Using Analog Computers, Levine, LoCCN 63-1794
4. Analog Computer Programming, Rekoff, LoCCN 67-22999
5. Design Fundamentals of Analog Computer Components, Howe, LoCCN 61-8536
6. Basics of Analog Computers, Truitt and Rogers, LoCCN 60-10469
7. Analog Computer Techniques, Johnson, LoCCN 63-16196
8. Electronic Analog and Hybrid Computers, Korn and Korn, LoCCN 63-23389
9. Differential Equations and Linear Algebra, Strang, ISBN 978-0-9802327-9-0
10. A First Course in Differential Equations, Zill, ISBN 0-534-41878-3
11. Calculus, Larson, Hostetler and Edwards, ISBN 0-618-14180-4
Some of these predate the ISBN system, so I list the Library of Congress Catalog Number. I purchased most of these on eBay. The two “classics” of analog computing are 7, by Johnson, and 8, by Korn and Korn. 6, by Truitt and Rogers is very interesting and relatively easy to read. It was written by two engineers from EAI, an analog computer manufacturer.
I hope this helps.
Cool! Ever run across this old digital computer idea that used compressed air to compute , patent 3190554?
Not specifically. In the literature I've read, pneumatic and hydraulic analog computers were mentioned briefly, but only electronic computers were covered in depth. I just finished "Analogue Computers" by K. N. Dodd, where the last chapter covered "Fluidics." That was a fascinating topic. There were pneumatic computers invented that included amplifiers, resistors, and integrators for the analog side, and digital logic gates and flip-flops on the digital side, all based on compressed air. They could be manufactured using printed circuit techniques. Apparently, their advantage is they weren't as susceptible to shock, vibration, temperature or radiation as electronics. I've run across a Foxboro pneumatic analog computer on eBay from time to time, but I have no way to apply it, since my background is in electronics.
This says Remington Rand was into this and the links at the bottoms show that it was giving some thought by lots of smart guys. www.google.com/patents/US3190554 I have asked around to see if N.A.S.A was ever into this but so far nada. Bet this would make a cool 3D printing project for some Tech High School kids. If Babbage had this tech he could have had the pipe organ folks build his engine for him and Lady Lovelace could have invented COBOL . ( I think that is kinda funny so I post it when I can) Dig the old kit "computer" Geniac . The guy who posted it calls it "A story in digital. " Now on to see if anybody has posted something on Collision Based Computing using Bristle Bots.
sir can i know which book helps me to understand analog electronics from basics
Mohan Besetty, a book I like is Elementary Electricity and Electronics Component by Component, by Mannie Horowitz, ISBN 0-8306-0853-2. It is at the basic technician level and does not require a lot of math background. It can be found on eBay for less than $10. Another great book is The Art of Electronics, by Paul Horowitz and Winfield Hill, ISBN 9780521370950. This book is more expensive, but I’ve seen the second edition on eBay for less than $50. The third edition might be better, but I think the second edition is very good. I have the Kindle version. Another very useful resource you might want is MicroCap SPICE simulation software. It is available for free here: spectrum-soft.com/download/download.shtm. This is a very good professional tool for simulating circuits. It includes an extensive reference manual and many example circuits. I use it every day and find it very useful for both learning and for designing new circuits.
Good luck.
Hello sir thanku for replying i was interested and fascinated in analog electronics escp in op amp i want to extend my knowledge can you suggest me a book i was undergrade first year student
I have purchased many op amp books over the years, but I have two favorite books that I recommend. First, an older book, Operational Amplifiers Theory and Practice, by James K. Roberge. Mr. Roberge was a professor at MIT, and they posted a video course he made in the 1985 called Electronic Feedback Systems, covering operational amplifiers.
Here’s a link to the MIT videos: th-cam.com/play/PLUl4u3cNGP62in17jH_DiJMkCGNM6Xni-.html
The second book is Design with Operational Amplifiers and Analog Integrated Circuits, by Sergio Franco. I have the third edition which is a little old, published in 2002. This book is very good. It covers op amp basics and many application circuits.
The book by Franco is listed on eBay for less than $10 in the US (some people charge much more, so be sure to sort by price if you go that route). The book by Roberge is more expensive. I find it interesting for historical context, but if you have to choose one, I’d recommend the Franco book.
I hope this helps. Good luck.
how does this work from m1076
Analog is derived from a Latin word meaning model
Isn't analog theoretically faster than digital?
Sorry it took me a while to get to this. You are correct. In fact analog computer operation is nearly instantaneous, in that the output of the op amp starts as soon as the computer is set to operate. Technically, the op amps all work in parallel, so the final output is instantaneous as well. Digital computers must perform operations serially, for the most part, so, at least in operation, the analog computer has s speed advantage. I think the reason they fell out of favor, though, is partly due to the time and care required to program an analog computer. Some of the problems in aeronautics required patching hundreds of op amps, and associated potentiometers and function generators. When the time taken to program them, and "debug" the program, digital computers eventually gained an advantage, especially when higher level programming languages became available. I've seen articles on the web about using analog computing methods for some functions in modern computers, now that Moore's Law is petering out, but I'm not sure if anything will come of it. That's interesting, but a bit beyond my scope.
Tim Thompson modern analog seems crazy, yet satisfying. Though if I were sky net ild go with cmos or some metal oxide variant.
@@timthompson468 Moore's Law?
Whats your take now that analog may make a come back because of AI?
Sir can you say a place where I can learn circuit analysis completely like vedio lectures you know please refer me
Mohan Besetty, I taught myself linear circuit analysis by reading a book, so I am not familiar with any videos on the subject. If you search on TH-cam, there are quite a few videos on the subject. You might try viewing a few of them to see if you like one. Here is one I took a quick look at that seems pretty good: th-cam.com/video/sqxzQkAdJm0/w-d-xo.html. The Kahn academy has videos on the subject, and I think they do good videos.
If you’re interested, the book I used to learn circuit analysis (recommended to me by a former boss), is Circuit Analysis, Allan D. Kraus, ISBN 0-314-79500-6.This book requires some knowledge of calculus, but it teaches you circuit analysis with differential equations and the Laplace transform. Another book that was recommended to me is Circuit Analysis, Irving L. Kosow, ISBN 0-471-03067-8. I have not read the Kosow book yet, but it has limited calculus topics that I can find in it. I purchased both of these books on eBay in the past five years, but I could not find either of them listed there or on Amazon today.
Good luck.
so to me this seems like a fancy kind of calculator. not really a general purpose "computer" as we would think of them... so you would not be able to make a "hello world" program with this. or a game. it's just used to solve certain kinds of mathematical problems - yes?
Thanks for watching. You are, for the most part, correct. The analog computer predates digital computers, and it was used primarily to quickly solve differential equations. Another name fo the analog computer was differential analyzer. The were also used to simulate control systems. It was much faster, though less precise, than the early digital computers, but it is very different in operation and application. The earliest digital computers measured their speed in seconds per operation instead of operations per second, so it was impractical to use them in solving differential equations using numerical methods. The output of the analog computer is a plot of the output of the solution to the differential equation, whereas in modern digital computers, the solution is the equation itself. In analog computers there is still a distinction between general purpose and special purpose. The GP-6 is considered a general purpose computer because it can be programmed for a variety of applications. In the Apollo era, NASA had an analog computer based lunar lander simulator which would be an example of a special purpose analog computer. With resources and clever programming, a reasonable graphics display can be made, but that’s beyond my capabilities. There is a video on TH-cam of a car suspension simulation that displays a simple car model driving down a road with simulated bumps. That’s very impressive considering the technology, but it’s nothing like what a modern gaming computer could do.
are you still around, can you reply to this if youre able to help me with a problem starting in analog, i have all the eqp. i beginning to suspect my computer is malfunctioning
First, thanks for watching. I am still around, and I might be able to help, if the problem isn't too complex. I'm trying to get back into making videos; I can't believe it's been four years since I posted one. Time flies. Let me know what your issue is, and what equipment you're using.
Sir can I buit my own analog system
Yes, but it would not be easy. If you search for “Comdyna GP-6 Manual” you can find the pdf of the manual for the one I use which includes schematics and wiring diagrams. You could feasibly adapt that for modern components. The hard part is you would need very good, low-leakage capacitors, a lot of multi-segment wafer switches and several 10-turn potentiometers. These components are very expensive, especially if you use the ones found in the GP-6. It’s possible to improvise but the results might not be as good. If I were to try it, I would also use less expensive interconnect components than the banana jacks on the interface panels of the GP-6. The system is modular, so it’s possible to start with one op amp/integrator, get that circuit working and then copy that to make as many integrators as is required.
WOW!! Could these analog computers from the 50's and 60's multiply/divide numbers? I mean, digital computers can't compute really well things like 10*0.1....
Thanks for watching. There were functions to multiply and divide, through various means. In some cases they would use a servo motor, but later an electronic multiplier was developed. The GP-6 has an electronic multiplier. I don’t remember off the top of my head what the IC was, but it was commonly used in the 70s. The multiplier can be used in reverse to perform division. If you look at my videos titled “Sounds of Chaos” I use the GP-6 multiplier there to program the Lorenz equation. I’m using it to modulate a Moog synthesizer, but you can see the chaotic Lorenz equation plotted on the oscilloscope. Thanks again.
@@timthompson468 Thanks also for your detailed answer to my question :) :) :)
but can it play crysis?
Well done but it would be a lot easier to follow with a schematic on the side. Spaghetti wiring is too hard to keep track of.
Thanks for the suggestion. Sorry it took so long to get back to you, but work has been hectic, and I've had to neglect the channel. I agree. I tried showing a wiring diagram from the manual in some of the videos, but that is hard to follow too. I'll try making symbols based on the analog computer texts in LTSpice to show the schematic of the analog computer solution in future videos. There might not be enough real estate to show them side-by-side, but I can do an overlay when explaining the circuit.
Who needs digital anyway!
You to make a comment on youtube
Do these come with instructions
Eric Johnson, the units I’ve purchased on eBay did not come with instructions, but if you search for “Comdyna GP-6” you will easily find pdf versions of the original manual. The manual is relatively short, but has complete operating instructions as well as schematics of all the circuits. The only issue is that, although the GP-6 evolved substantially over the years, I’ve only seen one version of the manual online, so the schematics in the manual might not match a particular unit that is purchased today. The operating instructions don’t change at all over the various units that have the digital meter display, so for the purpose of operation, the manual will work for any such unit. The manual is also a good source for learning the basic operation of any analog computer. I hope that helps, and thanks for watching.
Thanks I'd like to get one just to play around with and come up with crazy schematics by the way I have no calculus knowledge at all
Show me how to use JS on this machine!
So, analog computers are as advanced as digital computers of the 70's?
Can you get me Aubrey Plazas autograph?
Thanks
all I heard was acceleration due to gravity.