The No-CPU Computer Gets A C Compiler

April 26, 2019 by Brian Benchoff 24 Comments

C is the most perfect language and it will run on anything. It will even run on a computer without a CPU.

The computer in question here is the Gigatron, a fully-functional ‘home computer’ the likes of which you would find in the late 70s and early 80s, complete with a VGA output. What makes the Gigatron exceptional is the fact that there is no microprocessor; everything is just a RAM, a ROM, and a bunch of logic chips. There is no ALU chip. Or rather, there is; it’s just that an entire RISC CPU is implemented in basic logic chips and a whole lot of microcode on the ROM. It’s weird, yes, but it is cool. We’ve taken a look at the Gigatron before, and with this computer you get a glimpse of how clever engineers could have been if there were massive memories available in the late 70s.

While the Gigatron can be programmed in BASIC, the limiting factor of this computer is the fact that it remains exceptionally difficult to program. This is what the 8-Bit Guy says, and even though you can write some simple programs, it’s nothing compared to the likes of an Apple II or C64. If only there were a proper IDE, indeed if only there were a C compiler. That’s where [pgavlin] comes in. He has the LCC compiler working on the Gigatron. This is technically a C compiler for a computer without a CPU, or a computer that is entirely CPU. Either way you look at it, this is impressive.

As far as examples and demos go, [pgavlin] has a demo of Conway’s Game of Life working, and a program that will put dots on the screen. It’s not much, and it’s very slow, but check out the video below.

This isn’t a complete implementation of C, as multiplication, division, mod, and arbitrary shifts left or right haven’t been written yet. Floating point support will probably never be completed, and there’s no shame in that. The hardware is limited due to the fact of the fragmented memory map, but this can be improved by upgrading the Gigatron to a 64k memory model.

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Making A Three Cent Microcontroller Useful

April 26, 2019 by Brian Benchoff 48 Comments

The Padauk PMS150C is a terrible microcontroller. There are only six pins, there’s only one kiloword of Flash, 64 bytes of RAM, and it doesn’t do multiplication. You can only write code to this chip once, and the IDE uses 8-bit ints. [Anders] got his hands on some of these chips and decided to do something useful with them. It turns out that you can do a lot with minimal hardware, such as driving 300 RGB LEDs with a three cent microcontroller.

There’s some work trying to make an Open Source toolchain for these chips, but [Anders] decided to just go with the manufacturer IDE and programmer. What to do with a three cent microcontroller, though? Obviously something blinky. [Anders] connected this microcontroller to a strip of Neopixels, or WS2812Bs, but instead of driving them by giving each pixel a few bytes of RAM, the entire strip is being bitbanged one bit at a time. It’s some clever code, and even if [Anders] won’t be able to send images to a gigantic graphic display made of Neopixels, it’s still a neat trick.

At three cents and nearly zero associated hardware, this is the cheapest microcontroller we’ve ever seen. Even the minimalist PIC and AVR parts are on the orders of dozens of cents per part, and they still only have the functionality of this three-cent part. The manufacturer’s page has more details on the microcontroller itself including the data sheet, and you can check out the sizzle reel of this project below.

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A Chandelier Guaranteed To Make Some Retro Game Hardware Collectors Wince

April 26, 2019 by Jenny List 14 Comments

If there’s one thing our community is good at, it’s re-imagining redundant old hardware, particularly in the field of classic gaming consoles and their peripherals. Dead consoles have become new ones, Powergloves have ventured into virtual reality, and light guns, well, they’ve become novelty light fittings.

The [JJGames] Nintendo light gun chandelier will probably make collectors wince who prefer their retro hardware pristine, but it’s certainly an eye-catching conversation piece. The twelve guns are carefully disassembled and the Nintendo electronics removed, before a bulb holder and teardrop lamp is installed. Wiring is completed with twist caps, the guns are joined at the grip with some metal strips and glue, and a chain for ceiling attachment completes the ensemble. A dozen pieces of ireplacable retro hardware sacrificed for a novelty, or a masterpiece of interior decoration? You decide, though we’d opt for the latter in the context of the retro games based business in which it sits.

Our favourite NES lightgun hack ever has to be [Seb Lee-Delisle]’s one that fires a real laser. Meanwhile [JJGames] have made it here before in a similarly wanton use of classic Nintendo plastic, with their urinal made from SNES cartridges.

Resistance Is Futile, You Want This LED Cube

April 26, 2019 by Tom Nardi 26 Comments

We’re suckers for a good desk toy here at Hackaday, so this 2019 Hackaday Prize entry from [Jack Flynn] certainly caught our eye. The idea is that by using professionally manufactured dual layer PCBs and only surface mount components, you can create a cube that has an LED matrix on each face and all of the electronics hidden within. We’re not entirely sure if there’s any practical application for such a device, but we know we’d certainly like to have one blinking madly away on our shelf regardless.

Before having any of the PCBs manufactured, [Jack] is putting a considerable amount of thought into the design so he doesn’t end up painting himself info a corner (which is of course eight times as bad when you’re building a cube). By importing the PCB files into OnShape, he’s able to “assemble” a virtual representation of the final product to better understand how everything will fit together. He wants to limit the amount of times the cube will need to be pulled apart, so everything from how it will sit in its 3D printed cradle to the placement of breakaway tabs that ensure the internal power switch is accessible are being carefully planned out.

The current design puts the “brains” on the bottom board, with every other panel holding a daisy-chained MAX7219 to drive its own individual 64 LED matrix. Initially the dimensions of the ATmega328p powered cube will be 42 x 42 x 42 mm, with a total of 384 LEDs. Ultimately, [Jack] hopes the modular nature of the design could allow the size of the cube to be increased, or perhaps even take on a different shape entirely.

Generally the LED cubes we see are of the more wiry variety, so it’s particularly interesting when they take on solid forms like this one. Given the nearly universal popularity of blinking LED gadgets, we think this particular project is well positioned to make the leap from one-off hack to a commercial product.

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Parametric Amplifiers And Varactors

April 26, 2019 by Al Williams 9 Comments

It is hard to imagine a time without active amplification. However, if you go back far enough, radio communications started in an era where generating RF required something like a spark gap and reception was only possible if the signal was strong enough at the antenna — like with a crystal radio. It would be a few years before tubes allowed both transmitted and receiving signals to be electronically amplified and longer still before transistors that would work at radio frequency appeared. However, even active devices have had their limitations and the parametric oscillator and amplifier are ways around some of those problems.

These were more popular in the 1970s when it was harder to get transistors that would work at very high frequencies. They are still useful when you need very low noise amplification. In addition, the same effect is used in optical devices and you can even observe the effect in mechanical devices.

What Is It Exactly?

The phrase parametric means that the amplification or oscillation occurs because of the change in a parameter of the system. A simple example would be a variable capacitor. We know the charge in a capacitor is equal to the capacitance times the voltage across the unit. That also implies that, if charge is known, we can know the voltage by dividing the charge by the capacitance. To put it in numerical terms, if a 0.1 farad capacitor has 12V across it, the charge is 1.2 coulombs. Suppose our input signal is 12V and we let the capacitor charge up to that value. Then we twist the capacitor’s knob to give it a value of 0.05 farad. The charge can’t change, so now we have 24 volts across the capacitor. That’s an amplification of 2 times. These values, of course, are not practical. Nor is it practical to twist a capacitor knob constantly to amplify. However, it is a good analog of how a parametric amplifier works.

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Hackaday Podcast 016: 3D Printing With Steel, Molding With Expanded Foam, QUIP-Package Parts, And Aged Solder

April 26, 2019 by Mike Szczys 3 Comments

Join Editors Elliot Williams and Mike Szczys to recap the week in hardware hacking. This episode looks at microfluidics using Shrinky Dinks, expanding foam to build airplane wings, the insidious effect of time on component solder points, and Airsoft BBs used in 3D printing. Finishing out the episode we have an interview with two brothers who started up a successful business in the Shenzhen electronics markets.

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.)

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A Farmer’s Guide To Technology

April 26, 2019 by Bryan Cockfield 6 Comments

One of the hardest aspects of choosing a career isn’t getting started, it’s keeping up. Whether you’re an engineer, doctor, or even landscaper, there are always new developments to keep up with if you want to stay competitive. This is especially true of farming, where farmers have to keep up with an incredible amount of “best practices” in order to continue being profitable. Keeping up with soil nutrient requirements, changing weather and climate patterns, pests and other diseases, and even equipment maintenance can be a huge hassle.

A new project at Hackerfarm led by [Akiba] is hoping to take at least one of those items off of farmers’ busy schedules, though. Their goal is to help farmers better understand the changing technological landscape and make use of technology without having to wade through all the details of every single microcontroller option that’s available, for example. Hackerfarm is actually a small farm themselves, so they have first-hand knowledge when it comes to tending a plot of land, and [Bunnie Huang] recently did a residency at the farm as well.

The project strives to be a community for helping farmers make the most out of their land, so if you run a small farm or even have a passing interest in gardening, there may be some useful tools available for you. If you have a big enough farm, you might even want to try out an advanced project like an autonomous tractor.