The 512 Gigabyte Floppy Disk

May 26, 2022 by Jenny List 79 Comments

There are times when a technology goes almost overnight as if in a puff of smoke, and others when they fade away gradually over time to the point at which their passing is barely noticed. So it is with removable media, while we still have the occasional USB flash disk or SD card , they do not come anywhere near the floppies, Zip disks, and CD-ROMs of the past in their numbers or ubiquity. If the floppy disk is just a save icon to you there’s still the chance to experience their retro charm though, courtesy of [Franklinstein]. He’s made a 3.5″ floppy disk that eschews 720 k, 1.44 M, or even 2.88 Mb, and goes all the way with a claimed 512 Gb capacity. We’re sure we can’t remember these from back in the day!

Of course as we can see in the video below he’s achieved neither an astounding feat of data compression nor a bleeding-edge method of storing bits in individual iron oxide molecules. Instead the floppy hinges open, and there’s a holder for micro SD cards where the disk itself would be. It’s a bit of fun, and we have to agree with him that it makes a very handy holder for micro SDs that can carry that much data. This sets us wondering though, whether it would be possible to somehow multiplex 14 micro SDs to a microcontroller on a PCB that could fit in a floppy shell. Perhaps an ESP32 could be a slow file server through a web interface?

He makes the point that 512 Gb of floppies would comfortably exceed the height of the tallest buildings were they stacked together, so at the very least this represents a space saving. If you’re looking for something slightly more functional and don’t mind modifying the drive, there’s always this classic approach to marrying a floppy with an SD card.

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An Illuminating Look At A Wolf 5151 Light Source

May 23, 2022 by Tom Nardi 8 Comments

While originally designed to put light where the sun don’t shine for medical purposes, [Nava Whiteford] says the Wolf 5151 Xenon endoscopic light source also works well for microscopy and general optical experiments, especially since you can get them fairly cheap on the second hand market. His cost just $50 USD, which is a steal when you consider a replacement for its 300 watt Olympus-made bulb will run you about 200 bucks alone.

That said, [Nava] recently moved on to a more compact light source, and figured that was a good enough excuse to crack open the Wolf 5151 and see what makes it tick. In this particular post he’s just looking at the optical side of things, which is arguably the most interesting aspect of the device. Helpfully, the whole assembly is mounted to its own sled of sorts that can be pulled from the light source for a closer examination.

Beyond that expensive bulb we mentioned earlier, there’s a thick piece of what appears to be standard plate glass being used as an IR and UV filter. [Nava] suspects this component is responsible for keeping the rest of the optics from overheating, which is backed up by the fact that the metal plate its mounted to appears to feature a K-type thermocouple to keep an eye on its operating temperature. Forward of that is a unique aspheric lens that features a rough spot to presumably scatter the light at the center of the beam.

Our vote for the most fascinating component has to go to the Neutral Density (ND) filter, which is used to control the intensity of the light. In a more pedestrian light source you could just dim the bulb, but in this case, the Wolf 5151 uses a metal disk with an array of holes drilled into it. By rotating the disc with a DC motor, the lens can be variably occluded to reduce the amount of light that reaches the aperture, which connects to the fiber cable.

While it’s perhaps no surprise the build quality of this medical gear is considerably beyond the commercial gadgets most of us get to play with, it still doesn’t hold a candle (no pun intended) to the laser module pulled from a Tornado jet fighter.

AVX-512: When The Bits Really Count

May 9, 2022 by Matthew Carlson 16 Comments

For the majority of workloads, fiddling with assembly instructions isn’t worth it. The added complexity and code obfuscation generally outweigh the relatively modest gains. Mainly because compilers have become quite fantastic at generation code and because processors are just so much faster, it is hard to get a meaningful speedup by tweaking a small section of code. That changes when you introduce SIMD instructions and need to decode lots of bitsets fast. Intel’s fancy AVX-512 SIMD instructions can offer some meaningful performance gains with relatively low custom assembly.

Like many software engineers, [Daniel Lemire] had many bitsets (a range of ints/enums encoded into a binary number, each bit corresponding to a different integer or enum). Rather than checking if just a specific flag is present (a bitwise and), [Daniel] wanted to know all the flags in a given bitset. The easiest way would be to iterate through all of them like so:

while (word != 0) {
  result[i] = trailingzeroes(word);
  word = word & (word - 1);
  i++;
}

The naive version of this look is very likely to have a branch misprediction, and either you or the compiler would speed it up by unrolling the loop. However, the AVX-512 instruction set on the latest Intel processors has some handy instructions just for this kind of thing. The instruction is vpcompressd and Intel provides a handy and memorable C/C++ function called _mm512_mask_compressstoreu_epi32.

The function generates an array of integers and you can use the infamous popcnt instruction to get the number of ones. Some early benchmark testing shows the AVX-512 version uses 45% fewer cycles. You might be wondering, doesn’t the processor downclock when wide 512-bite registers are used? Yes. But even with the downclocking, the SIMD version is still 33% faster. The code is up on Github if you want to try it yourself.

Hackaday Podcast 151: The Hackiest VR Glove, Plotting Boba Fett With Shoelaces, ECU Hacking, And Where Does Ammonia Come From?

January 14, 2022 by Tom Nardi No comments

Hackaday Editor-in-Chief Elliot Williams and Managing Editor Tom Nardi are back again to talk about all the weird and wonderful stories from our corner of the tech world. Canon had to temporarily give up on chipping their ink cartridges due to part shortages, and that’s just too perfect to ignore. There’s also some good news for the International Space Station as the White House signals they’re ready to support the orbiting outpost until 2030.

We’ll also look at an extremely promising project to deliver haptic feedback for VR, programming bare-metal x86 with the Arduino IDE, and the incredible reverse engineering involved in adding a DIY autonomous driving system to a 2010 Volkswagen Golf. Finally we’ll find out why most of the human life on this planet depends on a process that many people have never heard of, and learn about the long history of making cars heavier than they need to be.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download

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Finally, Tame The Si5351!

November 26, 2021 by Jenny List 12 Comments

The Si5351 is an extremely useful device, containing multiple clock generators with many versatile programming options that go well beyond its original purpose of providing a clock for digital circuitry. It has in particular found a spot in RF projects, where it provides a cheap and effective stand-in for a variable frequency oscillator in everything from receivers to VNAs. It’s fair to say that programming the Si5351 isn’t the easiest of tasks though, and joining the various attempts to make this simpler is [MR-DOS], who has created an Si5351 library for the STM32 range of ARM Cortex M processors. Fortunately for those afflicted by the semiconductor shortage there’s the advice that porting it to other architectures should only require the relatively manageable task of modifying the i2c function for the new hardware.

Instead of being a full abstraction layer for frequency generation, this library provides functions to give access to the nuts-and-bolts of the chip such as PLL dividers. Thus there’s a need to understand the workings of a PLL and calculate its parameters, while in return much more flexibility over the chip’s operation can be had. We like this approach even though it requires a little more work from the developer.

Over the years this device has attracted a variety of libraries, this isn’t the first we’ve featured.

Header image: Adafruit Industries (CC BY-NC-SA 2.0)

Learn DMX512 Basics

October 15, 2021 by Al Williams 11 Comments

If you’ve done anything with modern lighting effects, you’ve probably heard of DMX, also known as DMX512. Ever wonder what’s really happening under the hood? If so, then you should have a look at [EEForEveryone’s] video on the topic, which you can see below.

At the core, the DMX512 uses RS485, but adds software layers and features. The video uses the OSI model to show how the system works.

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An RGB Backlight For The Nokia 5110 LCD

July 4, 2020 by Tom Nardi 13 Comments

Hardware hackers love the Nokia 5110 LCD. Or at least, they love the clones of it. You can pick up one of these panels for a couple bucks wherever electronic bits and bobs are sold, and integrating it into your project is a snap thanks to all the code and documentation floating around out there. But while it might be cheap and reliable, it’s not a terribly exciting component.

Which is perhaps why [Miguel Reis] thought he’d spruce it up a bit with an RGB backlight. While we’ll admit that this hack is mostly about looking cool, it’s not entirely without practical application. If your gadget experiences some kind of fault, having it flash the LCD bright red is sure to get somebody’s attention from across the room.

The board itself is very straightforward, with four MHPA1010RGBDT RGB LEDs and a couple of passives to keep them happy. The Nokia 5110 LCD module just pops right on, and beyond the extra pins added for the three LED colors, gets wired up the same as before. The backlight LEDs just need a few spare GPIO pins on your microcontroller to drive them, and away you go.

[Miguel] is currently selling his RGB version of this iconic LCD on Tindie for only a couple dollars more than the standard version, so it looks like a pretty cheap way to add a little bling to your next project. (Tindie is owned by Supplyframe, which also owns Hackaday. But they didn’t put us up to adding this link.)