Author: John Elliot V

135 Articles

One ROM to rule them all.

Software Defined Retro ROMs

July 19, 2025 by 6 Comments

Here’s something fun from our hacker [Piers]: Software Defined ROMs.

In this series of three videos, [Piers] runs us through what a software defined ROM is, how to make them, and then how to use them.

As [Piers] explains, one frustration a retro technician will face is a failed ROM chip. In the era he’s interested in, there are basically three relevant kinds of ROM chip, all 24-pin Dual Inline Package (DIP):

  • 2364 ROM chip: 8KB; 1x chip-select line
  • 2332 ROM chip: 4KB; 2x chip-select lines
  • 2316 ROM chip: 2KB; 3x chip-select lines

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A photo of the circuitry in its case

GarageMinder: Automatic Garage Door

July 19, 2025 by 12 Comments

After getting a new car, [Solo Pilot] missed the automatic garage door opening and closing system their old car had. So they set about building their own, called GarageMinder. On the project page you will find a bill of materials, schematics, and some notes about the approach taken in various versions of the software. [Solo Pilot] also made the software available.

The basic hardware centers around a Raspberry Pi Zero W, but there are plans to switch to an ESP32. From the car side of things there are built-in continuous Bluetooth Low Energy (BLE) advertisement broadcasts, which the Raspberry Pi can detect. Building a reliable system on top of these unreliable signals is difficult and you can read about some of the challenges and approaches that were taken during development. This is a work in progress and additional techniques and approaches are going to be trialed in future.

If you’re interested in Bluetooth garage door openers be sure to read about using a Bluetooth headset as a garage door opener for your Android device.

Before Macintosh banner with stylized pixelated picture of one

Before Macintosh: The Story Of The Apple Lisa

July 18, 2025 by 14 Comments

Film maker [David Greelish] wrote in to let us know about his recent documentary: Before Macintosh: The Apple Lisa.

The documentary covers the life of the Apple Lisa. It starts with the genesis of the Lisa Project at Apple, covering its creation, then its marketing, and finally its cancellation. It then discusses the Apple Lisa after Apple, when it became a collectible. Finally the film examines the legacy of the Apple Lisa, today.

The Apple Lisa was an important step on the journey to graphical user interfaces which was a paradigm that was shifting in the early 1980s, contemporary with the Macintosh and the work at Palo Alto. The mouse. Bitmapped graphics. Friendly error messages. These were the innovations of the day.

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A photo of a fully assembled PVCSub.

PVCSub: A Submarine From The Plumbing Aisle

July 18, 2025 by 11 Comments

Today in the submersibles department our hacker [Rupin Chheda] wrote in to tell us about their submarine project.

This sub is made from a few lengths of PVC piping of various diameters. There is an inflation system comprised of a solenoid and a pump, and a deflation system, also comprised of a solenoid and a pump. The inflation and deflation systems are used to flood or evacuate the ballast which controls depth. There are three pumps for propulsion and steering, one central pump for propulsion and two side pumps for directional control, allowing for steering through differential thrust. Power and control is external and provided via CAT6 cable.

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Screenshot of the cheatsheet being developed in Inkscape

Improve Your KiCad Productivity With These Considered Shortcut Keys

July 17, 2025 by 15 Comments

[Pat Deegan] from Psychogenic Technologies shows us two KiCad tips to save a million clicks, and he made a video to support it, embedded below.

In the same way that it makes sense for you to learn to touch type if you’re going to be using a computer a lot, it makes sense for you to put some thought and effort into your KiCad keyboard shortcuts keys, too.

In this video [Pat] introduces the keymap that he has come up with for the KiCad programs (schematic capture and PCB layout) and explains the rules of thumb that he used to generate his recommended shortcut keys, being:

  • one handed operation; you should try to make sure that you can operate the keyboard with one hand so your other hand can stay on your mouse
  • proximity follows frequency; if you use it a lot it should be close to hand
  • same purpose, same place; across programs similar functions should share the same key
  • birds of a feather flock together; similar and related functionality kept in proximate clusters
  • typing trounces topography; if you have to use both hands for typing you have to take your hand off the mouse anyway so then it doesn’t really matter where on the keyboard the shortcut key is

You can find importable KiCad keymaps and customizable SVG cheatsheets in the downloads section.

[Pat]’s video includes some other tips and commentary, but for us the big takeaway was the keymaps. He’s also got a course that you can follow along with for free. And if you haven’t been keeping abreast of developments, KiCad is now at version 9, as of February this year.

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A photo of a Stirling Engine attached to a bike

Building A Stirling Engine Bike

July 17, 2025 by 27 Comments

Over on his YouTube channel [Tom Stanton] shows us how to build a Stirling Engine for a bike.

A Stirling Engine is a heat engine, powered by the expansion and contraction of a working fluid (such as air) which is heated and cooled in a cycle. In the video [Tom] begins by demonstrating the Stirling Engine with some model engines and explains the role of the displacer piston. His target power output for his bike engine is 150 watts (about 0.2 horsepower) which is enough power to cycle at about 15 mph (about 24 km/h). After considering a CPU heatsink as the cooling system he decided on water cooling instead.

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An old PC with CRT monitor

ProtoWeb: Browsing The Information Superhighway Like It’s 1995

July 17, 2025 by 19 Comments

Feeling nostalgic? Weren’t around in the 90s but wonder what it was like? ProtoWeb has you covered! Over on his YouTube channel [RetroTech Chris] shows you how to browse the web like it’s 1995.

The service that [RetroTech Chris] introduces is on the web over here: protoweb.org. The way it works is that you configure your browser to use the service’s proxy server, then the service will be able to intercept your browsing activity and serve you old content from its cache. Also, for some supported sites, you will see present-day content but presented in the format you would have seen in the 90s. Once you have configured your browser to use the ProtoWeb proxy you can navigate to http://www.inode.com/ where you will find a directory listing of sites which have been archived or emulated within the service.

In his video [RetroTech Chris] actually demos some of the old web browsers running on old hardware, which is a very good recreation of what things were like. If you want the most realistic experience you can even configure ProtoWeb to slow down your network connection to the speed of a 56k dial-up modem. There are some things from the 90s that we miss, but waiting for websites to load isn’t one of them!

We had a look in our own archive to see how far back we here at Hackaday could go, and we found our first post, from September 2004: Radioshack Phone Dialer – Red Box. A red box! Spicy.

Continue reading “ProtoWeb: Browsing The Information Superhighway Like It’s 1995” →