Neon Lamps Make For The Coolest Of Nixie Clocks

Revisiting old projects is always fun and this Nixie Clock by [pa3fwm] is just a classic. Instead of using transistors or microcontrollers, it uses neon lamps to clock and drive the Nixie Displays. The neon lamps themselves are the logic elements. Seriously, this masterpiece just oozes geekiness.

Inspired by the book “Electronic Counting Circuits” by J.B. Dance(ZIP), published in 1967, we covered the initial build a few years back. The fundamental concept of operation is similar to that of Neon Ring Counters. [Luc Small] has a write-up explaining the construction of such a device and some math associated with it. In this project, [pa3fwm] uses modern day neons that you find in indicators, so his circuit is also updated to compensate for the smaller difference in striking and maintaining voltages.

The original project was done in 2007 and has since undergone a few upgrades. [Pa3fwm] has modified the construction to make it wall mounted. Even though it’s not a precise timekeeper, the project itself is a keeper from its time. Check out the video below for a demonstration.

Feel inspired yet? Take a peek at the White Rabbit Nixie Clock and you are looking for a low voltage solution to powering Nixies then check out the 5-volt Nixie Power supply.

Continue reading “Neon Lamps Make For The Coolest Of Nixie Clocks”

Building a Tricorder Prop Worthy of Mr Spock

We’ve all been there. You want to assemble a proper Star Trek: The Original Series landing party prop set, but the TOS tricorders you can find on the market are little more than overpriced toys. Imagine the embarrassment of beaming down to Cestus III with a plastic tricorder. The Metrons wouldn’t have even bothered with the trial by combat with such a sorry showing.

Unhappy with the state of Star Trek props, [Dean O] decided to take matters into his own hands. He purchased a TOS tricorder from Diamond Select Toys and set out to modify it into something a bit closer to Starfleet standards. Anything painted metallic silver on the toy was replaced with a machined aluminum duplicate, adding some much needed heft. He even spruced up the controls and display.

To start, [Dean] stripped the tricorder down, separating all of the silver plastic parts and finding aluminum stock that was close enough to the desired dimensions. This ended up being .125″ plate for the sides, and .500″ bars for the horizontal dividers. To make the side panels he placed the original plastic parts over the aluminum, marked the mounting holes with a punch, and used the belt sander to shape them.

[Dean] then put in a more screen accurate Moire disc, and went as far as to get real watch crowns for the buttons (just like the prop used in the show). In a particularly bold move, he even drilled out the center of watch crowns to install plastic light pipes for LED illumination.

Last year we saw a build that crammed a Raspberry Pi into the same Diamond Select tricorder toy to excellent effect. Now somebody just needs to combine both projects and they’ll have the slickest tricorder in the Alpha Quadrant.

Making Fancy Dice PCBs at Home

These days, it’s easy to get high-quality custom PCBs made and shipped to your door for under $50. It’s something that was unfathomable only a decade ago, but now it’s commonplace. However, it doesn’t mean that the techniques of home PCB production are now completely obsolete. Maybe you live somewhere a little off the beaten track (Australia, even!) and need to iterate quickly on a project, or perhaps you’d like to tinker with the chemical processes involved. For your learning pleasure, [Emiliano] decided to share some tips on making SMD-ready PCBs with the TinyDice project.

The actual project is to create a small electronic dice, and [Emiliano] touches on the various necessary considerations such as how to decrease power consumption, and how to source good quality, organic random numbers from your local microcontroller. Though its far from an exhaustive discussion on either topic, it shows an understanding of the deeper factors at play here.

However, the real meat of the write-up is the PCB production process. The guide goes through several stages of etching to not only prepare the PCB but also to add solder mask and produce a solder paste stencil as well using an aluminum can. This gives the boards that colored finish we’re all used to and lets the boards be reflowed for easy SMD assembly.

It’s a tidy guide as to how to approach producing your own boards to be used with SMD components, and it’s complete with clear photos and instructions throughout. If you want to take your designs up another notch, why not consider putting your components inside the circuit board?

From Cop Car Data Terminal, To Retro Computer

It is possible that you will have lived your life without ever coming into contact with a Motorola MDT9100-T. The data terminal of choice for use in police cars across the globe was a computer with a full-sized QWERTY keyboard, a small CRT display, a mainboard sporting an Intel 386SX processor, and a custom version of Windows 3.1. [Trammell Hudson] and some friends from NYC Resistor scored some MDT9100s in an online auction and found them to be just too good an opportunity not to crack them open and see what could be done.

The custom Windows install could be bypassed with a DOS prompt for some period demoscene action, but [Trammell] wanted more. The 386SX wasn’t even quick when it was new, and this computer deserved the power of a BeagleBone! A custom cape was created on a prototyping cape to interface with the MDT9100 header carrying both keyboard and video. A bit of detective work revealed the display to be a 640×480 pixel mono VGA. The ‘Bone’s LVDS output can drive VGA through a resistor ladder DAC with the aid of an appropriate device tree overlay. The keyboard was then taken care of with a Teensy working as a USB device, resulting in a working Linux computer in the shell of an MDT9100.

It’s always good to see old technology brought up to date. Amusingly a couple of years ago we reported on the death of VGA, but retro projects like this one mean it’ll be a long time before we’ve heard the last of it.

Teardown: “The Oregon Trail” Handheld

If you were a school-age child in the 1980’s or 1990’s, you almost certainly played The Oregon Trail. Thanks to its vaguely educational nature, it was a staple of school computers until the early 2000’s, creating generations of fans. Now that those fans are old enough to have disposable incomes, we are naturally seeing a resurgence of The Oregon Trail merchandise to capitalize on one of humanity’s greatest weaknesses: nostalgia.

Enter the Target-exclusive The Oregon Trail handheld game. Priced at $24.99 USD and designed to look like the classic beige-box computers that everyone of a certain age remembers from “Computer Class”, it allows you to experience all the thrills of dying from dysentery on the go. Naturally there have been versions of the game for mobile devices in the past, but how is that going to help you when you want to make your peers at the coffee shop jealous?

But we’re not here to pass judgement on those who hold a special place for The Oregon Trail in their hearts. Surely, there’s worse things you could geek-out on than interactive early American history. No, you’re reading this post because somebody has put out a handheld PC-looking game system, complete with a simplified keyboard and you want to know what’s inside it. If there was ever a cheap game system that was begging to be infused with a Raspberry Pi and some retro PC games, this thing is it. Continue reading “Teardown: “The Oregon Trail” Handheld”

Respectfully Modifying the Amiga 500

Modifying the Amiga 500 to speed up access to RAM in a memory expansion pack is a well documented procedure, with guides on the process written in the early 1990’s when the hardware was only a few years old. But as they were written for contemporary hardware, they make no concessions for how one should be treating a vintage computer that’s now over 30 years old. In 1993, cutting traces on the Amiga 500 motherboard was just a last ditch effort to eek a few more months of service life out of an outdated desktop computer. But in 2018, it’s kind of like when that old lady tried to “restore” a fresco of Jesus in Spain; it might be done with the best of intentions, but you still screwed the thing up good and proper.

Such things don’t fly over at [Inkoo Vintage Computing]. There you can find a guide that details the impressive lengths one can go to if they want to perform the classic modification without any irreversible changes to the motherboard. To avoid the cut traces and soldered bodge wires, this version of the modification makes use of a novel adapter that breaks out the necessary connections on the 8372A chip.

The adapter is simply a homemade PCB with both male and female plastic leaded chip carrier (PLCC) connectors. The few pins on the chip that needed rerouting are exposed as solder pads on the adapter for easy wiring. There are even a couple jumpers on the adapter to turn the modifications on and off.

Not surprisingly, the trickiest part of building this adapter was sourcing the antiquated PLCC connectors. Assuming you can even find them, you are then left with the challenging task of soldering them together. Judging by the pictures on the [Inkoo Vintage Computing] page, it’s no walk in the park.

Another similar arrangement is used in the expansion bay of the Amiga, where a pin is virtually “cut” in the connector. A tiny PCB is soldered to a 3×2 header to reroute the signals, and another jumper is used to enable and disable the pin. Luckily, the long pins on the Amiga memory expansion are forgiving enough that the little board can fit in between them without breaking electrical contact.

We’re no stranger to the Amiga 500 around these parts. We’ve covered how to get the 1987-vintage machine online in the 21st century, as well as employing a Raspberry Pi to emulate the original floppy drive. You can even make your own faux-Amiga with a 3D printed case, if you suffer from a sort of existential dread when working on a computer that’s older than you are.