Building Your Own 8088 XT Motherboard

May 21, 2022 by Al Williams 47 Comments

There was a time when an XT-class motherboard — like the old IBM PC with an 8088 CPU — was a high-tech accomplishment. Now, something like that is easily within reach of the average hobby lab. [Homebrew8088] did it, and it looks surprisingly simple, especially compared to what passes for a motherboard these days.

The board will take an 8088 or one of the NEC chips and by default sports 512 K of RAM, a few ISA slots, a PC speaker, a USB hard drive, and a PS/2 keyboard connector. The board will fit in an ATX case. Not bad. You can see a video of the board below.

In fact, the channel has a lot of related videos and the main site has many interesting topics, like driving an 8088 or 8086 from a Raspberry Pi. The GitHub site has design files for KiCad along with a lot of other information. Some of this will be interesting even if you are just trying to repair an old motherboard or would like to design a new ISA card.

If you want to know why the PC used an 8088 instead of an 8086, we just covered that. What are you going to do with an old XT computer? How about IRC?

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Sound Generation Board Makes The Tunes

May 20, 2022 by Al Williams 4 Comments

[Mcjack123] has been getting into chiptunes lately and realized that his original interest started in 2018 when he used an Arduino to turn a TI-84 calculator into a sound machine. His latest iteration is a custom-designed soundboard and he takes us through the design and construction of it in a recent post.

The work models classic sound generators like the 2A03 or the Commodore 64 SID. You have a bunch of simple waveform generators along with filters and modulators to make various effects. These boards eventually gave way to FM synthesis devices like the Yamaha OPL2 and OPL3 chips. All of these cards accepted commands and generated audio on their own. More modern boards are more likely to simply convert digital data from the computer into audio.

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Scott’s CPU From The Bottom Up

May 19, 2022 by Al Williams 5 Comments

It isn’t for everyone, but if you work much with computers at a low level, you’ll probably sooner or later entertain the idea of creating your own CPU. There was a time when that was a giant undertaking, but with today’s tools and FPGAs it is… well, not easy, but certainly easier. If you have the urge to try your own, you might have a look at [Simply Explained’s] video series called “Building Scott’s CPU.”

The 11 videos cover everything from basic transistor logic to sequential circuits and moves on to things like ALUs, clock units, and how jump instructions work.

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Put A New Spin On Your 3D Printed Parts

May 19, 2022 by Al Williams 4 Comments

Once you get tired of printing keychains and earbud holders with your 3D printer, you’ll want to design things a bit more sophisticated. How about things that rotate? [3DSage] has a good how-to about how to integrate a simple motor and controller into a few different size boxes. Combined with some 3D printed linkages, these boxes can turn your project — printed or otherwise — into something that spins.

To demonstrate, he created a few cat toys, played with an idea for a magic trick, and refit a selfie light into… something. We have no doubt you can find something to do with these little motor modules. The boxes vary mostly in how big the battery packs are. There are also several interesting side pieces like a 3D holder for rechargeable button cells and their charger.

In addition, he also demonstrates how to use the motor as a (rather poor) generator. Attaching a water wheel wasn’t a success until he used compressed air to run the wheel. You would have thought water would have done the trick.

The video stresses that you should solder connections, but you don’t have to. Honestly, we think if you are building moving stuff with a 3D printer, you should probably just go ahead and learn to solder. It isn’t that hard and there are plenty of reasons to learn.

Of course, you could 3D print the motor itself. Adapting motor modules for different uses isn’t a new idea, of course, but it is always great to see more ways to apply basic components.

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Engineering Vs Pigeons

May 19, 2022 by Al Williams 36 Comments

We’ve all been there. Pigeons are generally pretty innocuous, but they do leave a mess. If you have a convertible or a bicycle or even just a clean car, you probably don’t want them hanging around. [Max] was tired of a messy balcony, so like you might approach any engineering problem, he worked his way through several possible solutions. Starting with plastic crows, and naturally ending with an automated water gun.

The resulting robotic water gun that targets pigeons with openCV is a dandy project and while we don’t usually advocate shooting at neighborhood animals, we don’t think a little water will be any worse than the rain for the pigeons. The build started with a cheap electric water pistol. A Wemos D1 Mini ESP8266 development board provides the brainpower. The water pistol wouldn’t easily take rechargeable batteries, plus it is a good idea to separate the logic supply and the pump motors, so the D1 gets power from a USB power bank separate from the gun’s batteries.

That leaves the camera. An old iPhone 6S with a 3D printed bracket feeds video to a Python script that uses openCV. If looks for changes using a very particular algorithm to detect that something is moving and fires the gun. It doesn’t appear that it actually tracks the pigeons, so maybe that’s a thought for version 2.

Was it successful? Maybe, but it does seem like the pigeons learned to avoid it. We still think azimuth and elevation on the gun would help.

Most of the time when we see pigeon hacking it is to use them for nefarious purposes. [Max] should be glad he doesn’t have to deal with lions.

MIDI Controller Looks Good, Enables Your Air Guitar Habit

May 18, 2022 by Al Williams 8 Comments

We all want to be guitar heroes, but most of us have to settle for letting a MIDI board play our riffs using a MIDI controller. [Joris] thinks a MIDI controller should look like a cool instrument and thus the Ni28 was born. Honestly, we first thought we were looking at wall art, but on closer look, you can see the fretboard and the soundhole are festooned with buttons.

Actually, they aren’t really buttons. The Ni in the name is because the buttons are nickel-plated brass plates that act like touch switches. There’s virtually no activation force required and you can easily touch more than one plate at a time.

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The Little Big Dogs Of Invention

May 18, 2022 by Al Williams 53 Comments

This is a story about two dogs I know. It is also a story of the U.S. Navy, aviation, and nuclear weapons. Sometimes it is easy to see things in dogs or other people, but hard to see those same things in ourselves. It’s a good thing that dogs can’t read (that we know of) because this is a bit of an embarrassing story for Doc. He’s a sweet good-natured dog and he’s a rather large labradoodle. He occasionally visits another usually good-natured dog, Rocky — a sheltie who is much smaller than Doc.

I say Rocky is good-natured and with people, he is. But he doesn’t care so much for other dogs. I often suspect he doesn’t realize he’s a dog and he is puzzled by how other dogs behave. You would think that when Doc comes to visit, the big dog would lord it over the little dog, right? Turns out, Doc doesn’t realize he’s way bigger than Rocky and — apparently — Rocky doesn’t realize he should be terrified of Doc. So Rocky bullies Doc to the point of embarrassment. Rocky will block him from the door, for example, and Doc will sit quaking unable to muster the courage to pass the formidable Rocky.

Big Doc…

Somewhat smaller Rocky….

It makes you wonder how many times we could do something except for the fact that we “know” we can’t do it. Or we believe someone who tells us we can’t. Doc could barge right past Rocky if he wanted to and he could also put Rocky in his place. But he doesn’t realize that those things are possible.

You see this a lot in the areas of technology and innovation. Often big advances come from people who don’t know that the experts say something is impossible or they don’t believe them. Case in point: people were anxious to fly around the start of the 1900s. People had dreamed of flying since the dawn of time and it seemed like it might actually be possible. People like Alberto Santos-Dumont, the Wright brothers, Clément Ader, and Gustave Whitehead all have claimed that they were the first to fly. Others like Sir George Cayley, William Henson, Otto Lilienthal, and Octave Chanute were all experimenting with gliders and powered craft even earlier with some success.

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