 OK, so I hope the sound is all right. And I want to tell you something about the design of printed circuit boards. To those who are not familiar with circuit boards, I will give a short introduction on the history and the evolution of printed circuit boards. And especially because I think it's significant some technical aspects on the exchange format used to transfer layout data, have a look at the design aspect beyond the pure functional design. And I want to show some experiments I did. And let's see if this is something interesting. So when researching this talk, I was basically looking in an online forum for electrical engineers and was telling a bit about what I'm going to do. And one of the responses I got, I found striking because he said, believe it or not, I'm genuinely interested to hear what you find out. But I'm afraid I think you may be looking for ideas and inspiration in a pretty dry, empty place. Sorry. So obviously, this person in his career has focused on the functionality over the design aspect. And the functionality, I think, has some inherent beauty. But to make nice looking board is not necessarily in the goals among the goals for the design. And I must say I don't buy his approach. I think he is somewhat limited by routine blindness. And even when not focusing on that, there are tons of implicit patterns and some sort of beauty in the design of PCBs. So yeah. And especially nice things happen when enthusiasts do their own PCBs in their free time. And they're investing vast amounts of energy into the beauty aspect of the design. And I want to showcase at least some of this. But mostly I'm focusing on industrial design. So why PCBs at all? This is from an old TV monitor from 1963. And you see that it has a vastly different appearance than the electronics you're used to today. And this kind of highlights what problem PCBs are designed to solve. You have some random stacks of components. They're needed some delicate soldering to get them together. They need to produce the correct schematics. And it's tricky to handle. You see it's really a mastership in creating something like this. You need to have an idea about the soldering as well as the electrical ideas behind it. And yeah, so this doesn't really help when you try to mass produce cheap stuff. So one of the first attempts looked like this. This is a so-called cordwood circuit. And it's to try to get a better reliability for the PCB. And if you have a closer look here, you also already see something like a trace. Yeah, which later will become the PCB. So this is some experimental PCB, which is done by the company Tektronix. It's pre-1966. It's not exactly clear when this has been designed. And this is one of the first attempts to improve the reliability and the production speed of their devices, in this case an oscilloscope. We'll later have a look at some of the details on that. So another aspect was that PCBs, in the beginning, focused on small components. So you had a module that gets plugged in somewhere. This might be a PCB. In this case, it's a so-called flip chip technology from a PDB-10. The year is 1971. And yeah, it's a small module with a few components on it. But you already can see that it's way more organized than the first one we saw. So these modules got plugged in into a so-called backplane. And the backplane from the other side looked like this. So this is from 1975. So you'd see the PCB production really did take a while until it really arrived in the market. This is done with some semi-automatic wire up with twisted pairs. So you see that the individual strands of the wires are actually two wires intertwined. And yeah, it was done with a huge amount of automation already. So you had wire instructions on a punched card or a punched tape. And yeah, this is how this was created. And it obviously worked good enough for quite a while. But it wasn't cheap, definitely not. So this is from 1969. And you see that the look you associate with PCBs already is there. You have these distinct 45 degree angles. You have various components bridging over other traces. And yeah, I think this already looks quite modern, although it is from the end of the 60s. And yeah, I didn't actually, I didn't expect that at that time. So how are PCBs produced? These are screenshots from an old educational movie, also done by tectonics. Basically, you had a clear film. And you had pre-made symbols. You would stick on the film. And then this guy actually uses a roll. You can see it here, roll of sticky tape to create a trace between the correct pads. So this work usually was done in an upscaled version, like 2 to 1 or 4 to 1. And then you got in and tweaked. Basically, here he is cutting the pads because they are too tight, too close to the trace in between. And so they got cut a little bit and lifted off. So it was a very hands- or down-to-earth manipulation of physical things you would put together and create a photographic film that's later used in the production. So yeah, this is tweaking. And then the film gets photographically reduced. And you use photosensitive materials to shape the areas of the copper base material to protect it from etching. This guy actually is using a pantograph drilling machine to place holes in the correct locations. And of course, relatively early, there was various attempts to automate this. So this is, wait, I'm sorry. Something is wrong here. OK, so pantograph drilling machine. So you can drill holes at the correct locations with a high precision. And yes, automation was quite early. This is also in the movie from 1969. And it uses punch tape to have instructions, for example, for the drilling machine. So later, they invented a so-called photoplotter made by a German scientific. It's basically a wheel of a purchase which in a controlled manner points light at a film. So you can use it for exposing the film. So you can have numerically controlled high precision film. So this is the command language. And I won't bore you with the details. Basically, the interesting point is you can have straight lines and circular segments. You don't have busy years, which from a point nowadays is quite a pity because this is still the format used for exchanging the data. To highlight the differences, this is about manually rooted. It's ZX81, the first edition. And I want to highlight the smooth shapes. And the third edition looked like this. So obviously, there has been a change in the way how it was manufactured because this definitely is cat use. This Amiga 500, here you can see that there are curves instead of hard corners. This is from an Apple Macintosh SE. Here you see the typical 45 degree angles. Yeah, and I think this really is beautiful. It comes from a highly technical demand. And yeah, but the outcome has a very specific aesthetic. I like a lot. So the point is PCBs are used for a function. In this case, basically carrying components. It's a lot of small SMD components. And here you see, if you look at these wiggly things, these things have a purpose. They're intended for length matching of the traces. So that high speed signals can be transferred with a high reliability. Again, something utterly beautiful, but not created for its beauty. And again, this is not an attempt that someone draw ventilators or something like that. This is basically HF Voodoo. So if you are working with very high frequency signals, these kind of traces can act as a filter. I don't have any idea how this works. It's really voodoo. So this is what a PCB looks like. If you have a cross-section, in this case, it is a four-layer PCB. The copper areas are shaped with a photographic process followed by some etching. Yeah, and it's called a four-layer PCB because it actually consists of 11 layers. So it's some silkscreen printing, some solar resist in between, some copper layers. And actually, the count of the copper layers is the relevant thing. So if you have a look here, there is the topmost copper layer, intermediate copper layer, another intermediate copper layer, and the down copper layer. The interesting thing is that this can be produced with a very high precision. And the copper can be gold-plated. And the top three layers, top four layers, are relevant for the visible artwork. So if you actually look at the tools used to design this stuff, they're not really equipped to deal with graphical content. They are focusing on the electrical signals. And so yeah, the limits, especially when looking at fonts, there are severe limits. Basically, fonts are constructed from straight lines. This was not always the case, especially if you look back in history, this is, again, the ZX81. And it has a beautiful font and silkscreen printed on top of it. So this is something that, at some point, happened when Cat has been introduced. So this is about this time. Obviously, the font looks quite ugly, straight lines cobbled together. But even here, there's some attempt at doing a logo artwork in case of the Commodore logo. And dealing with graphics is cumbersome with these tools. I'm looking at the Eagle tool later. There are open source alternatives, but they share the same restrictions. I'll skip over this now, because I'm a little bit in hurry. So this is the early PCB I showed. There is an attempt at the logo etching. This is done, obviously, with a photographic process. And it has quite a high detail, although this is over-etched. It's too much copper removed in the etching process. Again, logo Apple, of course, has put some efforts into producing a nice PCB. Yeah, let's just skip that. And this is what enthusiasts can do. If you have a close look, this is the Hypnotode from Futurama. And the traces are designed to recreate the shape and of this iconic tote. And it actually is a synthesizer that creates the drone sound. This is something I did. And this is where it actually all started. My experience started. This is from a small Blinkenleit simulator, if you're familiar with the Blinkenleit project. This is a black and white replica of the Frieze on the actual house, the Sleras in Berlin. And it's realized by solid copper, gold-plated, and then a dark violet solder mask is put on top of that. And that turned out quite nice. And if you need a scale, it's 32 millimeters wide. So let's have a look at the workflow. Let's take a black and white bitmap. There are scripts available to import these bitmaps into the layered tool, this screenshot from Eagle. And you see that the bitmap is replicated using straight lines. So you see the distinct stairs, stair step pattern. And you have a ton of lines in your design, which make it harder to actually produce the PCB, because there are certain steps which involve checks if the lines are correct and having this amount of individual lines makes that harder. As well as you can't get to arbitrary high resolutions, because there's a minimum trace with you have to respect. So yeah, you get this rasterized experience. So my attempt basically was look at the primitives. And we only have the circular segments while the graphics will basically relies on BCA curves. So one thing you can do is approximate BCA curves with circular segments. And this is what I did here. So you need quite a lot of segments to approximate this simple BCA. So this is the outcome. There are some additional tricks I did here. Basically, the shape is straight lines. It's a field polygon and filling is happening automatically in the workflow. So it looks like this. And you see that the text is a little bit too fat. So the next thing I did was to reduce the shapes, shrink the shapes. Actually, I did it in the wrong order here. And split up the holes, because polygons may not have holes. So this is the second attempt. And I think this looks quite better. A last look, since we are really short on time on text. This is how text properties are looking like in Eagle. We have lots of straight lines. And the text, in my opinion, is not really nice. Is it visible? Yeah. So Keycard, the open source alternative, is doing slightly better. They still have a font constructed from straight lines. But they have way more lines making nice round shapes. So I wrote this Python thing to try to construct the font from purely circles, circular segments. And this is what I did, to actually match the shape of lines with some original font. In this case, it is based on dried suns. Yeah. And when you use this with lots of tricks and lots of annoyances, you can get something like this. And the nice thing is, it's constructed from circular segments. And the amount of segments is not that much increased. But it's a manual process. You need to do manual design of the text. And yeah. So that's about it. I could show you the tool in action if time permits. But we can also start with questions. So question or demo? Question. Did you look at Fritzing? No. Because they actually have import. You can import arbitrary bitmaps. And it will rasterize them. And I think the implementation is really similar to what? I would have to have a look. And it does SVGs as well. And then it tries to, if the paths will fit the gripper, then it uses that. It might be worth looking at. And also, yeah. Second question? Nobody? OK. Thanks. Thank you very much.