Author: John Elliot V

110 Articles

Trekulator: A Reproduction Of The 1977 Star Trek Themed Calculator

April 21, 2025 by 9 Comments

A recent project over on Hackaday.io from [Michael Gardi] is Trekulator – Where No Maker Has Gone Before.

This is a fun build and [Michael] has done a very good job of emulating the original device. [Michael] used the Hackaday.io logging feature to log his progress. Starting in September 2024 he modeled the case, got his original hardware working, got the 7-segment display working, added support for sound, got the keypad working and mounted it, added the TFT display and mounted it, wired up the breadboard implementation, designed and implemented the PCBs, added some finishing touches, installed improved keys, and added a power socket back in March.

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A photo of Aaron Danner with a current mirror schematic in an overlay.

Biasing Transistors With Current Sources

April 21, 2025 by 3 Comments

Over on his YouTube channel [Aaron Danner] explains biasing transistors with current sources in the 29th video of his Transistors Series. In this video, he shows how to replace a bias resistor (and consequently an additional capacitor) with a current source for both common-emitter and common-collector amplifiers.

A current source provides electrical energy with a constant current. The implication is that if the resistance of the load changes the current source will vary the voltage to compensate. In reality, this is exactly what you want. The usual resistor biasing arrangement  just simulates this over a narrow voltage range, which is generally good enough, but not as good as a true current source.

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MilliForth-6502, A Forth For The 6502 CPU

April 20, 2025 by 41 Comments

Forth is popular on small computers because it is simple to implement, yet quite powerful. But what happens when you really need to shrink it? Well, if your target is the 6502, there’s milliForth-6502.

This is a port of milliForth, which is a fork of sectorforth. The sectorforth project set the standard, implementing a Forth so small it could fit in a 512-byte boot sector. The milliForth project took sectorforth and made it even smaller, weighing in at only 336 bytes. However, both milliForth and sectorforth are for the x86 architecture. With milliForth-6502, [Alvaro G. S. Barcellos] wanted to see how small he could make a 6502 implementation.

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Zynq-7000 banner.

Building A Custom Zynq-7000 SoC Development Board From The Ground Up

April 20, 2025 by 8 Comments

In this series of 23 YouTube videos [Rich] puts the AMD Zynq-7000 SoC through its paces by building a development board from the ground up to host it along with its peripherals. The Zynq is part FPGA and part CPU, and while it has been around for a while, we don’t see nearly as many projects about it as we’d like.

[Rich] covers everything from the power system to HDMI, USB, DDR RAM, and everything in between. By the end, he’s able to boot PetaLinux.

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This is the Rockbox logo banner.

Rockbox 4.0 Released

April 19, 2025 by 23 Comments

It’s traditional to launch new software on April Fool’s Day, which is when we heard that Rockbox 4.0 has been released. But, in this case, the venerable MP3 firmware actually did update after a long absence. It’s great to see that good old Rockbox is still kicking along. We first mentioned Rockbox here at Hackaday approaching 20 years ago. How time flies. There used to be a whole ‘scene’ around hacking Personal Media Players (PMPs), also known as “MP3 Players”.

We tracked down Rockbox contributor [Solomon Peachy] to ask for some simple advice: If someone wants to install Rockbox on a personal media player today, what hardware should they buy? [Solomon] referred us to the AIGO EROS Q / EROS K, which is the only compatible hardware still being manufactured and sold. Beyond that, if you want to buy compatible hardware, you’ll need to find some secondhand somewhere, such as eBay. See the Rockbox Wiki for supported hardware.

Smartphones and streaming services have subsumed the single-purpose personal media player. Will you put the new Rockbox on something? Let us know in the comments.

A nuclear coolant tower dwarfs other buildings in the area.

They Hacked A Nuclear Power Plant! Whoops! Don’t Make A Sound!

April 19, 2025 by 3 Comments

What do you do with an unused nuclear reactor project? In Washington, one of them was hacked to remove sound, all in the name of science.

In 1977, a little way outside of Seattle, Washington Nuclear Projects 3 and 5 (WNP-3 and WNP-5) were started as part of Washington Public Power Supply System (WPPSS, pronounced “whoops”). They ran over budget, and in the 80s they were mothballed even though WNP-3 was nearly complete.

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A broken bolt is removed by welding on a hut and then using a wrench to unscrew.

Using A MIG Welder, Acetylene Torch, And Air Hammer To Remove A Broken Bolt

April 16, 2025 by 13 Comments

If your shop comes complete with a MIG welder, an acetylene torch, and an air hammer, then you have more options than most when it comes to removing broken bolts.

In this short video [Jim’s Automotive Machine Shop, Inc] takes us through the process of removing a broken manifold bolt: use a MIG welder to attach a washer, then attach a suitably sized nut and weld that onto the washer, heat the assembly with the acetylene torch, loosen up any corrosion on the threads by tapping with a hammer, then simply unscrew with your wrench! Everything is easy when you know how!

Of course if your shop doesn’t come complete with a MIG welder and acetylene torch you will have to get by with the old Easy Out screw extractor like the rest of us. And if you are faced with a nasty bolt situation keep in mind that lubrication can help.

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