Teardown: The Oregon Trail Handheld

March 14, 2018 by Tom Nardi 80 Comments

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

March 12, 2018 by Tom Nardi 22 Comments

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traces on the Amiga 500 motherboard was just a last ditch effort to eek a few more months of service life out of an outdated desktop computer.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.

Open Source Hardware Video Game Music Player

March 12, 2018 by Tom Nardi 5 Comments

[Aidan Lawrence] likes classic synthesized video game music in the same way that other people “like” breathing and eating. He spent a good deal of 2017 working on a line of devices based on the Yamaha YM2612 used in the Sega Genesis to get his feet wet in the world of gaming synths, and is now ready to take the wraps off his latest and most refined creation.

One of his earlier attempts at a hardware VGM player.

The YM2151 Arcade Classic is an open source hardware player for Video Game Music (VGM) files. It uses no emulation, the files are played on the device’s YM2151 chip in the same way they would have been on a real arcade cabinet at the time of their release. Interestingly, as some arcade machines were exceedingly rare or even scrapped before release, [Aidan] believes that his player may be the first time some of these songs have ever been played (at least in public) on real hardware.

The YM2151 synthesizer is powered by a STM32 “Blue Pill” board, which was selected as much for its capabilities as it was its low cost. The STM32 loads the VGM files from an SD card, and puts track information for the currently playing song on the 128×32 OLED display. A few tactile switches under the screen allow for shuffling through the songs stored on the card, and a slide switch for mute rounds out the simplistic but functional user interface.

In the GitHub repository, [Aidan] has provided the source code, schematics, Bill of Materials, and KiCad-generated Gerber files; everything you need to create your own version of his player. After listening to it rock out for a few minutes in the video after the break, we’re tempted to take him up on that offer.

This player reminds us of a similar design, also using original hardware, that we covered last year. The logical next step for this project would be to flesh out the UI and put it into an enclosure like this SNES chiptune player.

Continue reading “Open Source Hardware Video Game Music Player” →

A Faster Grave Digger For Your Child

March 10, 2018 by Lewin Day 12 Comments

Children love speed, but so few of those electric ride on toys deliver it. What’s a kid to do? Well, if [PoppaFixit]’s your dad, you’re in luck.

This project starts with an unusually cool Power Wheels toy, based on the famous Grave Digger monster truck. During the modification process, it was quickly realised that the original motor controller wasn’t going to cut the mustard. With only basic on/off control, it gave a very jerky ride and was harsh on the transmission components, too. [PoppaFixit] decided to upgrade to an off-the-shelf 24 V motor controller to give the car more finesse as well as speed. The controller came with a replacement set of pedals, both accelerator and brake, to replace the stock units. On the motor side, a couple of beefier Traxxas units were substituted for the weedy originals.

Acceleration is now much improved, not just due to the added power, but because the variable throttle allows the driver to avoid wheelspin on hard launches. It also makes the car much more comfortable and safe to drive, thanks to the added controllability. Another way to tell the project was a success is the look of pure joy on the new owner’s face!

This was a fairly basic install, very accessible to the novice. These sort of electric vehicle hop-ups are commonplace enough that there are a wide variety of suppliers who sell easy-to-use kits for this sort of work. For that reason, we’ve seen plenty of hacks of this sort – like this modified scooter, or these Power Wheels set up for racing.

Continue reading “A Faster Grave Digger For Your Child” →

A Relay Calculator With DIY Neon Displays, Just Because

March 8, 2018 by Dan Maloney 3 Comments

This looks like one of those projects that started out as a glimmer of an idea and led down a rabbit hole. But it’s a pretty cool rabbit hole that leads to homebrew neon seven-segment displays on a calculator with relay logic.

It’s a little thin on documentation so far, but that’s because [Mark Miller]’s build is one of those just-for-the-fun-of-it things. He started with a bag full of NE-2 tubes and the realization that a 3D-printed frame would let him create his own seven-segment displays. The frames have a slot for each segment, with a lamp and current limiting resistor tucked behind it; with leads brought out to pins and some epoxy potting, these displays would be hard to tell from a large LED seven-segment. Rolling your own displays has the benefit of being able to extend the character set, which [Mark] did with plus-minus and equal sign modules. All of these went together into a two-banger calculator — addition and subtraction only so far — executed in relays and vacuum tubes. Version 2.0 of the calculator regressed to all-relay logic, which must sound great.

We heartily regret the lack of a satisfyingly clicky video, but we’ll give it a pass since this is so cool. We’ll be watching for more on this project, but in the meantime, if you still need to get your click on, this electromechanical BCD counter should help.

Hijacking A Sony Watchman For Pong

March 7, 2018 by Inderpreet Singh 10 Comments

The era of the vintage television was a great one, and one of the transitional by-products was the Sony Watchman. It was a portable TV which Sony started selling in 1982, and the amazing thing about it was that it had an actual 4-inch cathode ray tube or CRT. [Sideburn] just posted a video in which he hijacks the internals of a Watchman to make it into a portable game of Pong.

The hack begins with removing the TV tuner module inside to make some room for the new residents. Next comes the M51364P which is VIF video decoder chip, and for which surprisingly there is not a lot of info on the web. They were able to find a part of the schematic, which though it was in Russian may still be useful for enthusiasts. Removing the VIF revealed the audio and video pins that needed the appropriate signals for the hack to be successful. In an age of multilayer boards it is amazing how a two-layer PCB makes life so easier for the tinkerer.

For the new brains an Arduino Nano clone was selected, and instead of adding modern buttons the existing volume and band select switches were convinced to be the paddle control and play/pause button. Getting everything to fit was easy with the absence of the tuner module, and voila! New(ish) hardware. For the firmware, [Sideburn] turns to Hackvision firmware which has a host of games such as Space Invaders, Asteroids, and even Tetris.

We covered Hackvision a few years ago as a hardware/firmware bundle, and if you are more into CRTs then check out the Arduino driven 6845 CRT controller.

Continue reading “Hijacking A Sony Watchman For Pong” →

An Old Way To Make A New Crank Handle

March 3, 2018 by Kristina Panos 24 Comments

When the crank handle on [Eric Strebel]’s cheapo drill press broke in two, did he design and print a replacement? Nah. He kicked it old school and cast a new one in urethane resin.

In his newest video, [Eric] shows us his approach to molding and casting a handle that’s likely stronger than the original. The old crank handle attached to the shaft with a brass collar and a grub screw, so he planned around their reuse. After gluing the two pieces together and smoothing the joint with body filler, he packs the back of the handle with clay. This is a great idea. The original handle just has hollow ribbing, which is probably why it broke in the first place. It also simplifies the cast a great deal.

Here’s where things get really interesting. [Eric] planned to make a one-piece mold instead of two halves. At this point it becomes injection molding, so before he gets out the reusable molding box, he adds an injection sprue as an entry point for the resin, and a plug to support the sprue and the handle. Finally, [Eric] mixes up some nice bright Chevy orange resin and casts the new handle. A few hours later, he was back to drilling.

Crank past the break to watch [Eric]’s process, because it’s pretty fun to watch the resin rise in the clear silicone mold. If you want to take a deeper dive into injection molding, we can fill that need.

Continue reading “An Old Way To Make A New Crank Handle” →