Threaded Wires Save Phone Numbers

December 30, 2021 by Chris Lott 23 Comments

If you thought programming your 1990s VCR was rough, wait until you see this Russian telephone autodialer that [Mike] took apart over on the mikeselectricalstuff YouTube channel (video below the break). [Mike] got this 1980s Soviet-era machine a few years ago, and finally got around to breaking into it to learning what makes it tick. The autodialer plugs into the phone line, much like an old-school answering machine. It provides the user with 40 pre-set telephone numbers, arranged in two banks of 20, and a speaker to monitor the connection process. It uses pulse dialing — no touch tones. What’s surprising is how you program the numbers. Given that this was build in the 1980s Soviet Union, he wasn’t expecting a microcontroller. But he wasn’t expecting transformer core “rope” memory, either.

The phone normally sits on a platform on the left side of the machine. Raising up the platform exposes a bank of toroidal cores, arranged in seven rows of four. Each row corresponds to a dialed digit, and the four cores used to encode a single digit. At the top and bottom of the programming board are two 40-pin connectors, each pin corresponding to one of the preset phone numbers. A bunch of patch wires would have been provided, and you program each number by threading a long wire through the appropriate cores, connecting it at the top and bottom connectors much like a modern solderless breadboard. It’s also interesting to see the components and construction technique of this circuit board. For example, the diodes have the strip on the Anode end, not the cathode as we’re normally used to today. The transistor cans are mounted upside down like dead spiders.

Continue reading “Threaded Wires Save Phone Numbers” →

Customisable Micro-Coded Controller Helps With In-Circuit Debugging

December 30, 2021 by Dave Rowntree No comments

Over on Hackaday.io, [Zoltan Pekic] has been busy building a stack of tools for assisting with verifying and debugging retro computing applications. He presents his take on using Intel hex files for customised in-circuit testing, which is based upon simple microcoded sequencers, which are generated automatically from a high level description.

The idea is that it is very useful to be able to use an FPGA development board to emulate the memory bus component of the CPU, allowing direct memory access for design validation purposes. This approach will also allow the production of a test rig to perform board level verification. The microcode compiler (MCC) generates all the VHDL, and support files needed to target a Xilinx FPGA based dev board, but is generic enough to enable targeting other platforms with a little adaptation.

Another interesting use case enables in-circuit tracing of buggy memory accesses, with the microcode sequencer decoding the accesses and dumping the relevant information out to either a serial port, or even direct to an embedded VGA controller, hardware allowing.

This automated approach to generating customisable microcoded hardware is a very nice trick to have in your bag, and even if it only helps in certain circumstances, [Zoltan] notes that it at least serves as an interesting example of the architecture of computers from history, if not much else.

Source for the example 8085 project can be found on the project GitHub, and the toolchain source can found here also.

For an interesting practical use of microding to implement emulations of historical hardware, checkout this neat switchable reproduction calculator project.

Acordeonador, an 555 accordion powered by a CD player based genrator

CD Player Powered 555 Piano Goes Accordion To Plan

December 30, 2021 by Ryan Flowers 8 Comments

Ah yes, the 555 piano project. Be it the Atari Punk Console, or some other 555 based synthesizer, Hackers just love to hear what the 555 can do when attached to a few passives and a speaker. It’s a sound to behold. But for [Berna], that wasn’t quite enough! Below the break, you can see his creation, called the Acordeonador.

A portmanteau of the Spanish words for “Accordion” and Generator”, the Acordeonador does what no project we’ve seen so far can do: It turns a CD drive into a generator for a 555 based synthesizer.

To give the Acordeonador a more analog feeling, a large 4700uf electrolytic capacitor stores just enough energy to make the music generation more than an on/off affair. It’s a great effect, and it works well! Not being one to leave any details out, [Berna] prototyped the build on perf board and then covered the board in what appears to be an wood grained contact paper, giving it that 1970’s dual keyboard electric organ feel.

It really just goes to prove that a 555 project can be the source of a great time! Hackaday is rife with 555 projects, but if you enjoy this, be sure to check out The Most Important Device In the Universe, which is of course powered by a 555. Continue reading “CD Player Powered 555 Piano Goes Accordion To Plan” →

Taking A Close Look At Hawkeye’s Workbench

December 30, 2021 by Tom Nardi 51 Comments

We don’t have to tell you that the representation hackers and makers get in popular media is usually pretty poor. At this point, we’ve all come to accept that Hollywood is only interested in perpetuating negative stereotypes about hackers. But in scenes where the plot calls for a character to be working on an electronic device, it often seems like the prop department just sticks a soldering iron in the actor’s hand and calls it a day.

Of course, there are some exceptions. In the final episode of Marvel’s Hawkeye, the titular character is shown building some custom gear in a work area that looks suspiciously like somewhere actual work might get done. The set design was impressive enough that [Giovanni Bernardo] decided to pause the show and try to identify some of the tools and gadgets that litter the character’s refreshingly chaotic bench.

Now to be clear, we haven’t personally seen the latest Marvel spectacle from the House of Mouse, and it’s entirely possible that the illusion falls apart when taken as a whole. But from what we’re seeing here, it certainly looks like whoever did the set dressing for Hawkeye seems to have made an effort to recreate the hackerspace chic. We’ve got a multimeter within arm’s reach, the classic magnifying glass third arm, a Wiha screwdriver about to roll out of frame, and even some JB-Weld. If this looks eerily like what’s currently on your own bench, don’t worry, you’re not alone.

On the wider shot, we can see that the attention to detail wasn’t limited to the close-up. From the tools hanging on the pegboard to the shelves filled with rows of neatly labeled bins, we totally buy this as a functional workspace. It’s quite a bit neater than where we currently do our tinkering, but that’s more of a personal problem than anything. As we’ve seen, there are certainly people in this community who take their organization seriously.

Portrayals of science or technology in the media often leave a lot to be desired, which is why it’s so important to praise productions that put in the effort to get things right. With a little luck, maybe it will get through to the right people and raise the bar a bit. But even if it doesn’t change anything, we can at least give the folks behind the scenes some well-deserved recognition.

Electric Wheelchair Dump Truck Hack Really Hauls

December 30, 2021 by Ryan Flowers 5 Comments

Have you ever looked at a derelict electric wheelchair and thought “I bet I could make something great with that!” Of course you have- this is Hackaday, after all! And so did [Made in Poland], who managed to get a hold of a broken down electric wheelchair and put the full utility of his well equipped metalworking shop to work. The results? Lets just say it hauls.

What we really enjoyed about the build was that there wasn’t much that couldn’t be done by an average garage hacker with a drill press, angle grinder, and a stick welder. While it’s definitely nicer to have a lathe and a high quality welding table, plasma cutter, and everything in between, nothing that [Made in Poland] did in the video is such high precision that it would require those extensive tools. There may be some parts that would be a lot more difficult, or lower precision, but still functional.

Another aspect of the build is of course the control circuitry and user interface. Keeping the skid steer and castor approach meant that each motor would need to be controllable independently. To achieve this, [Made in Poland] put together a purely electromechanical drive controlled with momentary rocker switches and automotive relays to form a simple H-Bridge for each motor.

Of course you just have to watch until the end, because it really proves that a man will do anything to get out of hauling wood around! Old electric wheelchairs can also make a great base for big robots, as it turns out.

Continue reading “Electric Wheelchair Dump Truck Hack Really Hauls” →

Remoticon 2021: Uri Shaked Reverses The ESP32 WiFi

December 30, 2021 by Elliot Williams 9 Comments

You know how when you’re working on a project, other side quests pop up left and right? You can choose to handle them briefly and summarily, or you can dive into them as projects in their own right. Well, Uri Shaked is the author of Wokwi, an online Arduino simulator that allows you to test our your code on emulated hardware. (It’s very, very cool.) Back in the day, Arduino meant AVR, and he put in some awesome effort on reverse engineering that chip in order to emulate it successfully. But then “Arduino” means so much more than just AVR these days, so Uri had to tackle the STM32 ARM chips and even the recent RP2040.

Arduino runs on the ESP32, too, so Uri put on his reverse engineering hat (literally) and took aim at that chip as well. But the ESP32 is a ton more complicated than any of these other microcontrollers, being based not only on the slightly niche Xtensa chip, but also having onboard WiFi and its associated binary firmware. Reverse engineering the ESP32’s WiFi is the side-quest that Uri embarks on, totally crushes, and documents for us in this standout Remoticon 2021 talk. Continue reading “Remoticon 2021: Uri Shaked Reverses The ESP32 WiFi” →

When A Ball Robot Becomes Two Wheels

December 30, 2021 by Jenny List 8 Comments

It’s now about six years since Star Wars: The Force Awakens first showed us the little spherical robot BB-8, but it’s fair to say that along the way we’ve not lost our collective fascination for rolling-ball robots. There have been plenty of attempts to make a fully-rolling device, but perhaps [Derek Lieber] has a better take on it by turning a spherical robot into a two-wheeled roller by the addition of a pair of tyres. Inspired by a Samsung prototype that never made it to market, it works by the wheels working against the machine’s low centre of gravity, and using a tilt sensor to control speed.

The ball chassis is a 3D printed shell, into which after much experimentation with motors, the final version put a pair of gimbal motors with a set of magnetic position sensors. Inside is an Arduino Mega and a custom motor driver board sporting an LM6234, with an XBee radio for remote control. Meanwhile the power comes from a set of three LiPo cells, and there is some extra lead ballast in the bottom to keep the whole thing balanced.