Build A Barebones 68000

July 30, 2021 by Bryan Cockfield 32 Comments

The 68000 chip was ubiquitous in the computing world well past its heyday in the 1980s. It was used as the basis for many PCs and video game consoles, and even in embedded microcontrollers. Now, one of its niche applications is learning about the internal functions of computers. 68000 builds are fairly common when building homebrew computers from scratch, but projects like these can be complicated and quickly get out of hand. This 68000 project, on the other hand, gets the job done with the absolute minimum of parts and really dives into the assembly language programming on these chips. (Google Translate from Spanish)

[osbox68] built this computer by first simulating its operation. Once he was satisfied with that, the next step was to actually build the device. Along with the MC68008 it only uses two other TTL chips, a respectable 32 kilobytes of ram, and additionally supports a serial port and an expansion bus. A few 74-series chips round out the build including a 74HC574 used for debugging support. With a custom PCB to tie everything together, it’s one of the most minimal 68000 builds we’ve seen that still includes everything needed to be completely functional.

After all, including the TTL and 74XX chips the entire circuit board only uses 10 integrated circuits and a few other passive elements for a completely functional retro computer. [osbox68] also includes complete schematics for building a PCB based on these chips to make construction that much easier. Of course, emulating an old microcontroller instead of using TTL components can save a lot of real estate on a PCB especially if you’re using something like an FPGA.

Ask Hackaday: How Is The Chip Shortage Affecting You?

May 24, 2021 by Jenny List 133 Comments

Some friends of mine are designing a new board around the STM32F103 microcontroller, the commodity ARM chip that you’ll find in numerous projects and on plenty of development boards. When the time came to order the parts for the prototype, they were surprised to find that the usual stockholders don’t have any of these chips in stock, and more surprisingly, even the Chinese pin-compatible clones couldn’t be found. The astute among you may by now have guessed that the culprit behind such a commodity part’s curious lack of availability lies in the global semiconductor shortage.

A perfect storm of political unintended consequences, climate-related crises throttling Taiwanese chip foundries and shutting down those in the USA, and faulty pandemic recovery planning, has left the chipmakers unable to keep up with the demand from industries on the rebound from their COVID-induced slump. Particularly mentioned in this context is the automotive industry, which has seen plants closing for lack of chips and even models ditching digital dashboards for their analogue predecessors.

Chips on order everywhere on the Mouser website.

The fall-out from all this drama in the world’s car factories has filtered down through all levels that depend upon semiconductors; as the carmakers bag every scrap of chip fab capacity that they can, so in turn have other chip customers scrambled to keep their own supply lines in place. A quick scan for microcontrollers through distributors like Mouser or Digi-Key finds pages and pages of lines on back-order or out of stock, with those lines still available being largely either for niche applications, unusual package options, or from extremely outdated product lines. The chances of scoring your chosen chip seem remote and most designers would probably baulk at trying to redesign around an ancient 8-bit part from the 1990s, so what’s to be done?

Such things typically involve commercially sensitive information so we understand not all readers will be able to respond, but we’d like to ask the question: how has the semiconductor shortage affected you? We’ve heard tales of unusual choices being made to ship a product with any microcontroller that works, of hugely overpowered chips replacing commodity devices, and even of specialist systems-on-chip being drafted in to fill the gap. In a few years maybe we’ll feature a teardown whose author wonders why a Bluetooth SoC is present without using the radio functions and with a 50R resistor replacing the antenna, and we’ll recognise it as a desperate measure from an engineer caught up in 2021’s chip shortage.

So tell us your tales from the coalface in the comments below. Are you that desperate engineer scouring the distributors’ stock lists for any microcontroller you can find, or has your chosen device remained in production? Whatever your experience we’d like to know what the real state of the semiconductor market is, so over to you!

Tape Cutter Makes Short Work Of Through-Hole Resistor Reels

May 16, 2021 by Jenny List 9 Comments

As the world of electronics makes its inexorable movement from through-hole parts to surface-mount, it’s easy to forget about the humble wire-ended resistor. But a stack of them is still a very useful resource for any experimenter, and most of us probably have a bunch of them with their accompanying twin strips of tape. We’re entranced by [Sandeep]’s automated resistor tape cutting machine, which uses a fearsome looking pair of motorized knives to slice the tape into predetermined lengths.

At its heart is an Arduino and a set of stepper drivers, and it uses a PCB that he’s designed as a multipurpose board for motor-based projects. One motor advances the reel of resistors, while the other two operate those knives that simultaneously slice the two tapes. The whole is held in a wooden frame with 3D-printed parts, and control is through a touch screen. This feels more like an industrial machine than a maker project, and as can be seen in the video below, it makes short work of those tapes. Full details can be found on his website, including code.

We’ve not had so many through hole tape cutters, but we’ve seen at least one SMD cutter.

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Spare Parts Express

October 17, 2020 by Elliot Williams 33 Comments

I’ve got spare parts, and I cannot lie.

This week I’m sending out two care packages to friends and coworkers because I’ve got too many hackables on hand, and not enough time to hack them all. One is a funky keyboard, and the other is an FPGA dev board, but that’s not the point. The point is that the world is too interesting, and many of us have more projects piled up in the to-do box, with associated gear, than we’ll ever have time to complete.

Back in the before-times, we would meet up, talk about our ongoing hacks, and invariably someone would say “oh you need an X, I’ve got half a box of them” and send you one. Or maybe you’d be the one with the extra widgets on hand. I know I’ve happily been in both positions.

Either way, it’s a win for the giver, who gets to take a widget off the widget pile, for the receiver, who doesn’t have to go to the widget store, and for the environment, which has to produce fewer widgets. (My apologies to the widget manufacturers and middlemen.)

This reminded me of Lenore Edman and Windell Oskay’s Great Internet Migratory Box Of Electronics Junk back in the late aughts. Trolling through the wiki was like a trip down memory lane. This box visited my old hackerspace, and then ended up with Bunnie Huang. Good times, good people, good hacker junk! And then there’s our own Brian Benchoff’s Travelling Hacker Box and spinoffs.

These are great and fun projects, but they all end up foundering in one respect: to make sense, the value of goods taken and received has to exceed the cost of the postage, and if you’re only interested in a few things in any given box, that’s a lot of dead weight adding to the shipping cost.

So I was trying to brainstorm a better solution. Some kind of centralized pinboard, where the “have too many h-bridge drivers” folks can hook up with the “need an h-bridge” people? Or is this ad-hoc social network that we already have working out well enough?

What do you think? How can we get the goods to those who want to work on them?

Hackaday Podcast 083: Soooo Many Custom Peripherals, Leaving Bluetooth Footprints, And A Twirlybird On Mars

September 4, 2020 by Mike Szczys 3 Comments

Hackaday editors Mike Szczys and Elliot Williams ogle the greatest hacks from the past 168 hours. Did you know that Mars Rover didn’t get launched into space all alone? Nestled in it’s underbelly is a two-prop helicopter that’s a fascinating study in engineering for a different world. Fingerprinting audio files isn’t a special trick reserved for Shazam, you can do it just as easily with an ESP32. A flaw in the way Bluetooth COVID tracing frameworks chirp out their anonymized hashes means they’re not as perfectly anonymized as planned. And you’re going to love these cool ways to misuse items from those massive parts catalogs.

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 (60 MB or so.)

Continue reading “Hackaday Podcast 083: Soooo Many Custom Peripherals, Leaving Bluetooth Footprints, And A Twirlybird On Mars” →

The B-Sides: Curious Uses Of Off-the-Shelf Parts

September 2, 2020 by Sonya Vasquez 44 Comments

I admit: a few years of prototyping without easy machine shop access really whets my tastebuds for turning metal chips. But all that time spent away from proper machine tools has also pushed me to re-imagine part catalogs, something I see almost every day. Without any precision metalworking tools handy, stock mechanical parts have become my supplement for complexity. And so a former dogma to machine-everything-thyself has been transformed into a hunt for that already-made-part-that-does-it-for-you.

But with part catalogs featuring tens of thousands of purpose-built parts, I started reimagining some of them for other misdeeds. And after a few years spent reinventing use cases for some of these parts, I’m about ready to tell you how to misuse them properly. So today I’d like to show you some of my favorite mechanical part B-sides, so to speak. These are ordinary parts in unorthodox places–something you surely won’t find in the datasheet! Now let’s have a look. Continue reading “The B-Sides: Curious Uses Of Off-the-Shelf Parts” →

Control A Motor With A Touchpad

June 10, 2020 by Bryan Cockfield 11 Comments

There are a surprising wealth of parts inside of old laptops that can be easily scavenged, but often these proprietary tidbits of electronics will need a substantial amount of work to make them useful again. Obviously things such as hard drives and memory can easily be used again, but it’s also possible to get things like screens or batteries to work with other devices with some effort. Now, there’s also a way to reuse the trackpad as well.

This build uses a PS/2 touchpad with a Synaptics chip in it, which integrates pretty smoothly with an Arduino after a few pins on the touchpad are soldered to. Most of the work is done on the touchpad’s built in chip, so once the Arduino receives the input from the touchpad it’s free to do virtually anything with it. In this case, [Kushagra] used it to operate a stepper motor in a few different implementations.

If you have this type of touchpad lying around, all of the code and schematics to make it useful again are available on the project page. An old laptop in the parts bin is sure to have a lot of uses even after you take the screen off, but don’t forget that your old beige PS/2 mouse from 1995 is sure to have some uses like this as well.

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