 and welcome to Disc Alidieta. Hey everybody and welcome to my desk. It's me, Lady Aida. This is my desk covered and all sorts of stuff, including some floppy drives, which we'll be talking about shortly. Do you have any news or updates, Mr. Lady Aida, before we get to the next one? Lots of shows this week. Look to Hack a Day. I think we're doing a hack chat this week. Oh yeah, we're doing a hack chat. Yeah, so look for that and more and let's kick it off. It's under this this week. All right, so this week on my desk, we've got all sorts of floppy drives. I'm getting back to a project that I worked on, kind of a word, COVID part shortage time, which was integrating, interfacing with floppy drives. And this is like a laptop floppy disk and this is a desktop three and a half and this is an Apple. And I also have a five and a quarter floating around here somewhere, probably will fall in my head later tonight. So floppy drives are kind of neat. You can, there's a lot of people with floppy disk collections from like the 90s and it'd be really good to be able to get all that data off. And especially for like archival reasons, historical reasons, like I know my parents have a bunch of stuff on floppy. Now I'd love to keep that around because floppy disks do degrade like the magnetics start to, they can flake off or they can slowly become de-magnetized. So, we did this project and go to the computer where we wrote a bunch of code in CircuitPython and Arduino to kind of start the process of interfacing with floppies. And we did a bunch of videos and we're gonna get back to it. We just took a break basically like all these parts came back into stock and so we wanted to work on all those and all those redesigns. We did like 400 redesigns. Another thing is that the original code for the floppy stuff was all gonna be with a SAMD51 and like as I say like almost every video I can't get SAMD51s until 2024 like mid or late 2024. And that's like their current estimate which means, you know, whatever. I'll probably get some here and there but for the most part everything has to move over RP2040. So, you know, we did the floppy feather wing which was kind of just me getting like, okay, let's get something going so we can easily test it. And it's got a two by 17 header on one side and on the back it's got level shifters because floppy drives are all five volt logic and five volt power, we'll talk about in a minute. And so you need to, if you wanna interface with a three volt mic controller like the RP2040 you're definitely gonna want to have your up shifters kind of like Neopixels, right? You wanna go from three volts up to five volts. And that's where the 245 series comes in handy. Each one of these does eight bits. And, you know, floppy, you can look at some of the previous videos, but floppy disks are not, they have a very weird interface where the data streams out in this encoded bit width format it's very low level. And so you do need to have a very fast processor or PIO, which is why the RP2040 is actually really great for doing floppy interfacing stuff because you can use a PIO to read in these variable bit widths. It's kind of like reverse Neopixel, like the data's coming in and it's like, you know, a wide bit and a low like a, like it's up and down, up and down. And it's not like Manchester encoding, but it's like the width of the bit within the cycle tells you, the width of the pulse within the cycle tells you whether it's a one or a zero. So timer inputs are really good for it, but again, PIO will do the job as well. And then there's, you know, you have to step the motor and you have to set the direction and you can set which side, which head you want to read from. So a lot of pins are required to do this so that we got the floppy featherwing out, you know, a couple of months ago and it definitely works. Here it is, you know, plugged into your standard floppy drive, but there's a couple, there's a couple of things that while this was good, I wanted to do more. One, the floppy featherwing was hard-coded. The way I set up the direction was it could only read from, sorry, it could read right from diskettes, but it was meant to be connected to a floppy disk drive. It couldn't emulate being a floppy. And that's something that could be kind of interesting too. There's a lot of devices, you know, for example, I've worked with knitting machines and like a lot of knitting machines like the old Brother KH series require floppy drives. There's actually like a not insignificant number of old machines that expect you to have a floppy disk drive connected up to them. And so I know you can buy floppy disk emulators, but you know, I thought like, oh, like I really like doing open source hardware and making sure that we can have forever hardware, like this would, will always be able to be emulated or read. So even though you can buy this sort of thing off the shelf, I thought it would be kind of cool to re-implement it. So one thing about the floppy featherwing, like I mentioned, it can only connect to a drive, it can't act like a drive. Another thing, it isn't good for connecting to laptop floppy disk. So let's go to the overhead roll fast and I'll show this because it's kind of interesting. Okay, so you didn't know. So this is your standard, this is kind of handy, you can tilt this over and I can, you can see, pardon me, let me just get this. Okay. So this is your standard floppy interface. Right side up. So you see that this is a paper phenolic PCB and there's a little notch in it and there's even one pin missing, although most cables don't have the extra pin there and it's hard to hold it still. And these are the interface pins, so IF 2 through 34, so it's a two by 17 connector and every other pin is grounded. So like one row is all grounded and then the rest are like, it's basically like data stepper, index, direction, right protect, right enable, whatever, all the pins are on this top end. And then you also have the power, just kind of nice here, it's connected these three and a half inch only use five volt, they don't use 12 volts, but the larger disc drives do the five and a quarters use 12 volts and five volts. So even though this one only has five volts here, it's not uncommon to need 12 volts as well. Laptop floppy drives are much smaller and you can even see, you can see this beautiful little stepper motor here, which is used to feed the head back and forth. And then there's another spinning motor, it's very flat, but there's a very flat motor over there, which spins and also uses five volts, but instead of having this big chunky-ass connector, it has this, I think it's 24 pin FPC one millimeter pitch. So it has a slightly different connector, but it was interesting, it's actually easier to get laptop floppy drives are much more available than the chunky PC tower style. So I also wanted to make sure that the board that I designed has a connector for the laptop style and the five volt comes through here as well, by the way, which is a kind of handy, you don't need a separate connector for them. And then in addition to that, I also wanted to support weird drives like five and a quarter Apple style. So I've got this, I'm sorry, a little dusty, but this is in a clear case, which means you can really see the dust. And it's just got this custom controller, which is beautiful designed by Waz. And then on the end, it's got a, I don't know, two by 12, I think, two by 10 connector, which has, I think, plus minus 12 and five volts. And then four raw stepper pins, like you get the bipolar stepper pin control. So you don't do like direction and step. You're like, hi, I am like toggling each pin. And then the data streaming out similar style as the laptop or desktop style. And then a couple other, probably control signal pins and whatever. So I wanted to also connect to these. So this is another connector. And then while I was there, I was like, you know what? Like maybe I'll also have it be able to connect to SCSI. Discs, IDE, I feel like you can get IDE to SATA converter. So like that's not much value, but SCSI could be useful. So back here. Okay, so let's go to the computer and I'll show my draft so far. So it's really like I've just been slowly putting things down, you know, thinking about it. So the size of the PCB is the size of a standard floppy disc, you're gonna have inch floppy. So I've got the laptop flop. So this is the, no, I'm like what, how many pins is it? 26 pin, one millimeter pitch laptop connector. This is your standard two by 17 IDE floppy drive like your standard PC floppy disc. And this is SCSI, which is like 50 pins. By the way, do you guys remember that? It's an 8080 style. So it has eight bits of data, read latch, write latch, IRQ, busy, whatever, all those pins. It seems like, oh my God, 50 pins, but every other pin is ground, which, you know, they didn't have differential, they didn't use differential signaling at the time. So instead they would just ground every other pin to avoid having crosstalk. And then this is the, I think this is the maintenance lock amp 350211. So this is the standard connector used for powering like disc drives and floppies. And we have these, these are called like, I think I call them molex IDV, oops. So they're like this connector, right? Which is your standard. This is what this plugs into that connector. And what you can do is you can get, it's easy to get like splitter. So this is a splitter that goes from that power connector to floppy, but you can get ones that are like multiple ones. Basically it's an adapter because this is the floppy disconnector, you know, ground, 12 volt, five volt. And this is the, you know, molex to Berg. Although they're not, it's not molex. It's like apparently amp, I don't know. It's a very weird, the names of these are not consistent. Anyways, but you can get these, these cables are easy to get. So I thought I would put this connector on here. I was going to actually do a right angle one. It's just, just to kind of remind me not to forget putting this power connector here because it'll stick down, not up, but I put this here just to kind of give me the placement. And then I have to do, there's going to be like a lot of level shifting. Like obviously I'm going to share, there's not enough pins to do all of them at the same time. So what I'll have to do is kind of interleave whatever pins, so you obviously don't get to floppy in a SCSI and a disc too, all at the same time. You'd pick whichever one you want to connect. And then I'd have enough GPIO on here to connect to, definitely to connect to SCSI because don't forget you lose four pins to the QSPY interface. And then you need two pins for I squared C. And then I want a micro SD card micro SD card. I thought I had a couple of ideas. One, if you're emulating a device, obviously you could have your files on the micro SD card. But I thought it would also be kind of neat if it did standalone floppy disk greeting, because normally what you do is you connect this to your computer and then you run grease weasel or whatever on your computer and it sucks the data off and it saves it to your disk drive. But I could see there situations where you're like, look, I'm going to go to a place and maybe I don't have, I want to do a lot of them. And I don't want to get, because you only have one kid to your computer at a time. If you want to do multiple in parallel, you can't do it. But these standalone, maybe with some buttons, you know, you have some buttons here, you could control it. And then there's a STEM IQT port here. You can connect an OLED and, you know, or maybe I could like take advantage of the Scheddy connector and you can like connect a display that way somehow or something. But then when you plug in your disk drive, you can say dump the raw data or dump the IDE, the PC fat, you know, red data or try to read it as fat. If you manage to read all of it without any CRC errors, cool. If not, then, you know, I can go and get a raw data dump. So that could be useful because you can put any size micro SD card here for a lot of storage. And then Neopixel and I'm going to have like some LEDs for three volt, five volt, 12 volt power. For the disk two, I'm going to need to also, yes, two by 10. I'm also going to need a negative 12 volt power. I think it's, yeah, it's plus minus 12. The negative 12 is not like a high current output. It's used for biasing the trimmer that is like used for tweaking like either the speed or like the offset. There's like this trimmer on the board because they're sort of like, what's the 12 volt used for? And then you can, you know, it's just a small amount of current. So I'll need 12 volt high current because for big disk drives, the motor is usually 12 volt, five volt high current, negative 12 volts, like not so high current. And then of course, three volt for the RP2040 over here. So I'm still, you know, working on it. Kind of thinking like picking and choosing the components. You know, Neopixel, Stemic UT, I think I'll have enough GPIO for all this. Like I haven't like really started doing serious noodling, but I'm pretty sure there's enough. One thing I did is I wired up the micro SD card as SPI or SDIO because I thought that could be handy if you needed high speed reading. Now, usually don't get higher speed writing with SDIO because the write speed of a MMC, of a SD card is based on how fast you can erase blocks on the internal mic controller. So, you don't get a lot of benefit for doing SDIO for writing usually, unless you have like a high speed card, like a card that's designed for high speed erasing like for cameras, but for reading, it could be good. And if, you know, we did verify that this pinout works. Like you can have the SPI and SDIO pins interleaved and you can use either one with the SD card. And then, you know, put eight megabytes of Q-SPY flash. Maybe if you're doing just a couple, you're reading like one disk, you could read it and save it to the internal flash memory or you could like emulate from internal flash memory because we have really good support for that. And then, yeah, I think so that, you know, it's kind of nowhere near ready. I mean, for the, I got to start wiring up these. This is a, again, because I want to have it be bi-directional, you can either read or emulate. I need to have a full three to five volt bi-directional translator. So, I've used these before, the 74LVC HT series. So, you get two power pins, VCC A and VCC B, and it can do high to low. They're probably wondering, why don't you just use a TXB-0108? Doesn't the TXB-0108 do everything? No, the TXB-0108 does not handle pull-ups. It freaks out and I'm not, I think the TXB-108 and friends are very, very cool, but they're not good for a situation like this where the direction should be fixed. Like you, it shouldn't auto-detect which direction because again, it'll be weirded out by pull-ups. It's weirded out by signals that aren't like purely digital and I think sometimes when you're reading, you've got these 2.2K pull-ups on the floppy and I think like it's just gonna be freaked out by them because a lot of this is open drain. And the TXS series is also like kind of weird. So, I'm gonna go with this and just I'm gonna have to manually control the direction. And I might have a switch, like a mechanical switch. So it's like, hey, do you wanna have it emulator mode or in reading mode, like interfacing mode and then you can switch between the two of them. So the goal here is just to have, you know, I may not get every interface working in both directions, but the idea is to have like a truly open source hardware, easy to manufacture all in one board that kind of does every retro interface. I don't know, maybe I'll throw on some headers. You can do like a Commodore 64 interface too, which is like your, it's very weird. It's not, it's not any of these lower level interfaces. Anyways, so, you know, kind of like poking and prodding and it's gonna take me a couple of weeks to get this together because there's just a lot going on. Now, the thing I was thinking about that would be super freaky is if I have two extra GPIO, I could put a USB type A port and then you could plug in a USB key because that can be kind of fun too. Like if you're doing emulating or dumping of floppy disk images, you wouldn't even use a micro SD card. You could dump it straight to a USB key and then pull it out and like, you know, plug it into your computer or so because we've got USB host working with mass storage on the RP2040 pretty well. So some kind of weird stuff. So lots of pin configuration is gonna be needed, but I think these are the interfaces I'm gonna go with the laptop. Two by 17 floppy, two by 50 SCSI, so two by 25 SCSI and two by 10 disc two. And then of course, if you have a SCSI, you know, a D sub, you can get adapter cables that I'm not worried about that would go from this or maybe I'll sell something that like plugs in and gives you SCSI connector output. All right, so that's some floppy stuff. Any questions, Phil or? Keep going. Keep going. Okay, cool. All right, well, let's go into the great search and we'll talk about the five volt power supply. The great search part too, by Dick Chiqui and Ada Frude, every single weekly data user power of engineering, I hope you guess you find the things you want on dickchiqui.com. Lady Ada, what is this weeks? Great search. Okay, so I'm working on this board that's going to interface with floppy disk drives like this one or like I don't know if you think this. Apple II disk two. And these are devices that need a lot of power. They need five and 12 volts and they need them at a couple amps a piece because they're driving motors, spinning them around very fast. And you need to have a good clean power supply that's five volts and 12 volts. And, you know, historically, you could get these power adapters that would give you both five and 12 and they would actually plug in even directly into the disk drive itself. But those are actually kind of expensive and they're very specialized. And so I thought in this design for this board that's going to interface with disk drives, Apple II or floppy or whatever that instead of trying to like get this custom source five plus 12 volt power adapter, what I would do is say, you just provide me five volts, sorry, 12 volts at three or four amps you can get 12 volt, three or four amp power adapters or USB-C can provide 12 volts at three amps as well. And I'll give you the three, I'll give you the three, two to three amp five volt output as well as that 12 volts. And then, you know, you're good to go. You don't have to have a good dual supply. I'll generate the five from the 12. So let's go to the computer and I'll show. This isn't the final design but I wanted to sort of draft it out. So you'd have your 2.1 millimeter DC jack and again, you can get 12 volts power supplies very easily. I'll add an E fuse here. We'll cover that probably next week on the great search about how to do E fusing because I want to make sure that people don't plug in more than 12 volts into here and accidentally, you know, put 12 volts into the motor because I don't want to have a buck converter also for 12 volts and I don't want to have a SEPIC. I don't want to spend the extra money when I'd rather have a fuse and just be like, hey, just make sure you use a 12 volt. I won't let you use anything else and then I'll give you the five volt high current as well. So there's USB-C, but again, USB-C does not, even, you know, yes, if you have a power delivery setup, you can kind of guarantee getting five volts at two or three amps, but I'd rather just again, generate it from this chunky 12 volt power supply and use the USB just for communication to the computer and not try to use it for power input because again, you need a lot of current. You need like two amps, one amp, but let's say two to be safe. And so normally, you know, if I'm trying to get, you know, five volts from a 12 volt power supply on something like, you know, a Metro or something, I'll use like an AZ-1117 series. These are very, very common. I'll give you about one amp, 1.25 amps linear and they come in your standard Saat 223 or Saat 89. They're very inexpensive. You can see they're about 10 cents a piece in quantity, but, and they come in fixed as well. So I can get, you know, I can say, I want a fixed five volt output. Show you a couple of options. Yes, the AZ-5, 10 cents a piece and they work great. You know, you can get one amp out and the voltage drop is pretty minimal. I think it's yeah, about 1.3 volts. So definitely we'll get you current out of 12 volts. The problem is that any amount of heat we're dissipating out of this is pretty high. So you're 12 minus five, seven volt drop times, you know, 1.2 amps. Okay, eight watts. You're not gonna easily dissipate eight watts from this little package. You could do it with a TO220 with a really big ass heat sink, but you're definitely not gonna be, like this chip is not gonna be happy. It'll give you five volts, one amp maybe from like seven to nine volts, okay? But not from 12, even though the voltage rating can go up to 15 and that's something to watch out for. Like when I was younger and I was starting out, I was like, oh, it says I can do 15 and it'll give me five at one amp. Like it should work, right? But just because the technical limits let you do it, doesn't mean the thermal limits will match. So for this kind of situation, this is where you wouldn't want a buck converter. This is a perfect example of you want a high voltage convert to low and you can't dissipate that much power. Also it's a bit of a waste, right? I have to provide both five and 12 volts to, you know, a disc two power, Apple disc two floppy drive. So I don't want to like linearly lose two amps from my 12 volt power supply into the five volt regulator, even if I did have a gigantic heat sink because I still need two amps from the 12 volt as well. So, you know, if I use a buck converter, I can draw 400 milliamps from the 12 volt. I just need a less power, less big power supply. So cost, power, everything savings, the buck converter's the way to go. So let's look at a DC-DC buck converter and what you got, there's a lot of options. So there's just FYI, don't forget, they're switching controllers and switching regulators and switching converter. Like there's like a lot of things that sounds very, very similar. So these converters tend to be modules and there's nothing wrong with using modules. Sometimes you're like, I don't want to go through like getting inductors and stuff. You can get this chunky module from SparkFun or you can get this plug-in style and there's nothing wrong with these. They can be very inexpensive. However, I want to keep it low cost and the power requirements here aren't too high. So let's do a regulator that will also regulate the output. The controllers, by the way, usually you need to connect up a separate transistor and these are often used for extremely high current or extremely high voltages where you need the transistor to be specced for some, maybe 40, 50 volts or whatever and you wouldn't get that with a regulator but 12 to five, that's pretty common, by the way. Like you're gonna see there's 1000 options. So the regulator will give me a regulated output. So many options, 30,000 and a lot of them are in stock too. So let's look at only the active ones and let's look at the ones that are normally stocked and let's exclude the marketplace one. So this gets us down to like a paltry 7,000 options. Okay, and definitely there's tons and there's in stock. It's amazing, it's a beautiful thing. So we want surface mount because I'm gonna pick and place it onto this board. I want it to be definitely not negative. I want it to be positive, but sometimes positive or negative, whatever. I'll just select all of these. So all positive and then I want, I only need one output. Although, it could be interesting if I did need a lot of current at three volts, I could get a dual output that would give me 12 to five and 12 to three, but I don't actually need that much current at three volts. I'm gonna just toss an LDO on there. To convert the five volts to three volts because I only need like at the most 50, maybe 100 milliamps. Not worth getting another more complicated buck setup going on. Okay, so let me apply. I didn't even get rid of that many, there's so many options. Okay, so the next thing is do I want synchronous rectifier or not? So normally I would say, oh, I don't mind putting a diode in, I'll show you the freewheeling diode. You know, I picked this old design that I had. So like this design with the TPS 510, there is a freewheeling diode here, but it's another component and these are not inexpensive. They're 10, 10, 15 cents. So let's go with, yes, let's do a synchronous rectifier. Why not save one component? Also means usually there's a true disconnect between input and output, usually, at least it does with the boost converters. Okay, and then I definitely want not boost, I want buck only, so select those, okay? There's really, you know, almost everything will do what I want. Voltage input, the minimum. Well, it's gonna be 12 volts input, so let's make sure that I can handle 12 volts or less. And then input maximum, let's make sure the maximum can be, oops, 14 volts or higher. I don't know, 150 cares. Let's see if that, okay, now we're getting down to 2,600. Let's look for only ones that are tape and reel. Just, you know, I'm gonna put this on the pick and place and we'll get, you know, avoid the did you reel and cut tape version or tray versions, okay? And I think like that's pretty good. Voltage outputs, they all kind of cover five volts. So, you know, I mean, again, this is like one of the most common converters. All right, so let's look at the pricing quantity for 1,000 pieces. I don't like to give me a sense and get 2,000 options. There's a lot of options, so you don't have to worry about that. Oh, and then current output, duh, forgot the most important thing. So the motors on these, they are usually spec'd for one amp, but you know, I wanna make sure I have plenty of space in my power budget. So I'm gonna make the current outputs or the switch output be two amps or more because while this is this floppy, these floppies are one amp, there could be older ones that are less efficient and they could spike up and maybe draw like two amps. So let's do two amps and up, I don't know, 50 amps is kind of the bunkers, but we'll see. Okay, so now, now we're doing good. Okay, so lots of in-stock options and one thing I noticed is there's a couple of, you know, popular winners here. There's the AP622 series from Diodes Inc. And notice that book covers are really inexpensive, like 13 cents, 10 cents, about the same price as the LDO, which is another thing. It's like by the time you add the heat sinking to your linear regulator because you have to get a separate heat sink, it could be the same price as just getting, this is a synchronous buck. So all I need is the input capacitance, output capacitance and a couple of inexpensive passives to set the output voltage and, you know, an inductor. But the inductors are usually, you know, maybe 10, 10, 15 cents. This is very inexpensive. And there's a lot of good options. There's three volt out, sorry, three amp out, two amp out. I did see like there's a lot of like, there's the TPS562202 and then the TPS6227. And I was like, what's the difference between these two? And so I opened up the data sheets because I was like, I was like, expecting this to this week. And I was like, what is the difference between these two? So a lot of it is the accuracy of the output feedback and also the frequency. These are 580 and of course, the lower the frequency, the more efficient, but the bigger the inductor. So if you want a small inductor, you'll want higher frequency, but usually get lower efficiency. So it's a kind of a trade-off, but 600 kilohertz isn't too bad. And also the voltage range input and output. So this is 4.317. These are actually kind of very similar. I don't even know what are the differences between the two? And then, yeah, I don't even know. Soft start, hiccup mode, non-latch. I don't know the difference between the two. These two, pre-bias function. I don't know. You can also check out on TI. These seem like almost identical. This is that thing. I wish there was a little bit more clear what the differences are between the two. But the second digit, so there's 5.6, which is the TPS 5.6, which is the series. Two is two amp, three is three amp. So at the same price, they also get a three amp version, by the way. There's also this, the 62201. You see the datasheet. Yeah, so this output output range is 0.76 to seven volts. And this is 0.8 to seven. So like this, this light, they all, clearly they're all very, very similar. They have the same vets inside and the same kind of configuration and pin out. But they have slightly different pin numbers. I don't know. Some of them maybe have different compensation on the inside. All that looked pretty good though. I think, you know, I'm one of the people who I definitely can be convinced by what the crowd is doing. So actually decided of all these, I think the diodes one is good, but I kind of like this one just because these two, because both of these have like 100,000 and 20,000 in stock. So they're very promising. You could also go to the power designer, which is what if you want like more specific component selection. And what I put in here is the VIN like 10 volts to 14 volts and the output five volts and then 1.5 amps. And then let's just say low cost. And the TI web bench will generate, you'll actually, you'll see the same part number show up but it'll calculate for you, your inductors, the capacity that you want for ideal stability and the feedback resistors. Thankfully, you don't have to compensate the design. So I'll let this run in the meantime it'll generate the designs. But I think that this one is kind of what I'm gonna go with the TPS 562202 or 2201. And you can see here is the, my screen is very small, but you can see it generated of this same family, the 563, 563, 564, so it goes up to four amps. It likes to, I will say that the TI web bench looks to kind of give you a bigger than maybe necessary power budget. But you can follow this and you can see like, you know, entire bomb cost of like 51 cents. It's a really good deal. These are also higher frequency chips. It looks like the 5622 is of the 202. But they're all good. I think this whole family will probably work quite nicely. Very simple, very small and fairly good efficiency at V out five volts, you know, up to two amps, about 92%, which is about as good as you're gonna get. So yeah, I think that this is what I'm gonna go with the TPS 5622 series. So I'm gonna get this into my design. Then next week, we'll do the EFUSE for protection of this chip to make sure that you don't get more than about 12, 14 volts coming in. And that's a great search. All right, thank you so much for joining us this Sunday. We'll see everybody during the week. There's the floppy drive on the computer. That's right. See everybody during the week, we'll have to post some more. Thank you so much for supporting us and an independent open source hardware company in New York City. We very much appreciate it. Bye everybody. Bye everybody. Have a great week.