Author: Al Williams

4349 Articles

Clone Wars: IBM Edition

January 14, 2026 by 28 Comments

If you search the Internet for “Clone Wars,” you’ll get a lot of Star Wars-related pages. But the original Clone Wars took place a long time ago in a galaxy much nearer to ours, and it has a lot to do with the computer you are probably using right now to read this. (Well, unless it is a Mac, something ARM-based, or an old retro-rig. I did say probably!)

IBM is a name that, for many years, was synonymous with computers, especially big mainframe computers. However, it didn’t start out that way. IBM originally made mechanical calculators and tabulating machines. That changed in 1952 with the IBM 701, IBM’s first computer that you’d recognize as a computer.

If you weren’t there, it is hard to understand how IBM dominated the computer market in the 1960s and 1970s. Sure, there were others like Univac, Honeywell, and Burroughs. But especially in the United States, IBM was the biggest fish in the pond. At one point, the computer market’s estimated worth was a bit more than $11 billion, and IBM’s five biggest competitors accounted for about $2 billion, with almost all of the rest going to IBM.

So it was somewhat surprising that IBM didn’t roll out the personal computer first, or at least very early. Even companies that made “small” computers for the day, like Digital Equipment Corporation or Data General, weren’t really expecting the truly personal computer. That push came from companies no one had heard of at the time, like MITS, SWTP, IMSAI, and Commodore. Continue reading “Clone Wars: IBM Edition” →

Ask Hackaday: Do You Curb Shop Components?

January 13, 2026 by 63 Comments

I’m not proud. When many of us were kids, we were unabashedly excited when trash day came around because sometimes you’d find an old radio or — jackpot — an old TV out by the curb. Then, depending on its size, you rescued it, or you had your friends help, or, in extreme cases, you had to ask your dad. In those days, people were frugal, so the chances of what you found being fixable were slim to none. If it was worth fixing, the people would have probably fixed it.

While TVs and radios were the favorites, you might have found other old stuff, but in those days, no one was throwing out a computer (at least not in a neighborhood), and white goods like refrigerators and washing machines had very little electronics. Maybe a mechanical timer or a relay, but that’s about it.

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Electronic Nose Sniffs Out Mold

January 12, 2026 by 16 Comments

It turns out, that mold is everywhere. The problem is when it becomes too much, as mold infestations can have serious health effects on both humans and animals. Remediation is extremely expensive, too. So there are plenty of benefits to finding mold early. Now, German researchers are proposing an electronic “nose” that uses UV-activated tin oxide nanowires that change resistance in the presence of certain chemicals, and they say it can detect two common indoor mold species.

The nanowire sensors can detect Staachybotrys chartarum and Chaetominum globosum. The real work, though, is in the math used to determine positive versus negative results.

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Michelson Interferometer Comes Home Cheap

January 12, 2026 by 17 Comments

We suspect there are three kinds of people in the world. People who have access to a Michelson Interferometer and are glad, those who don’t have one and don’t know what one is, and a very small number of people who want one but don’t have one. But since [Longest Path Search] built one using 3D printing, maybe the third group will dwindle down to nothing.

If you are in the second camp, a Michelson interferometer is a device for measuring very small changes in the length of optical paths (oversimplifying, a distance). It does this by splitting a laser into two parts. One part reflects off a mirror at a fixed distance from the splitter. The other reflects off another, often movable, mirror. The beam splitter also recombines the two beams when they reflect back, producing an interference pattern that varies with differences in the path length between the splitter and the mirror. For example, if the air between the splitter and one mirror changes temperature, the change in the refraction index will cause a minute difference in the beam, which will show up using this instrument.

The device has been used to detect gravitational waves, study the sun and the upper atmosphere, and also helped disprove the theory that light is transmitted through a medium known as luminiferous aether.

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Design Of Common Emitter Amplifier

January 11, 2026 by 4 Comments

It used to be a rite of passage to be able to do the math necessary to design various bipolar transistor amplifier configurations. This doesn’t come up as often as it used to, but it is still a good skill to have, and [Void Electronics] walks us through a common emitter amplifier in a recent video you can see below.

The input design parameters are the gain and the collector voltage. You also have to pick a reasonable collector current within the range for your proposed device that provides enough power to the load. You also pick a quiescent voltage which, if you don’t have a good reason for picking a different value, will usually be half the supply voltage.

The calculations are approximate since the base-emitter voltage drop will vary by temperature, among other things. But, of course, real resistors won’t have the exact values you want, or even the exact value marked on them, so you need a little flexibility, anyway.

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The SCSI Film Scanner Resurrection

January 11, 2026 by 15 Comments

[Ronan] likes 35mm film photography, but the world, of course, has gone digital. He picked up an Epson FilmScan 200 for about €10. This wonder device from 1997 promised to convert 35mm film to digital at 1200 DPI resolution. But there was a catch: it connects via SCSI. Worse, the drivers were forever locked to Windows 95/98 and Mac System 7/8.

In a surprise twist, though, [Ronan] recently resurrected a Mac SE/30 with the requisite SCSI port and the System 7 OS. Problem solved? Not quite. The official software is a plugin for Photoshop. So the obvious answer is to write new software to interact with the device.

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ESP With EEG — No, Not That ESP!

January 10, 2026 by 13 Comments

While EEG research might help you figure out extrasensory perception, we won’t be betting on it. However, if you want to read EEG data and use an ESP32, [Cerelog-ESP-EEG] might be the right project for you. The commercial project is an 8-channel biosensing board suitable for EEG, EMG, ECG, and brain-computer interface studies. However, the company says, “We love the hacker community! We explicitly grant permission for Personal & Educational Use.” We love you too.

They do require you to agree not to sell boards you are building, and they give you schematics, but no PC board layout. That’s understandable, although we’d guess that achieving good results will require understanding how to lay out highly sensitive circuits.

Continue reading “ESP With EEG — No, Not That ESP!” →