The Rise And Fall Of Free Dial Up Internet

March 18, 2026 by No comments

In the early days of the Internet, having a high-speed IP connection in your home or even a small business was, if not impossible, certainly a rarity. Connecting to a computer in those days required you to use your phone. Early modems used acoustic couplers, but by the time most people started trying to connect, modems that plugged into your phone jack were the norm.

The problem was: whose computer did you call? There were commercial dial-up services like DIALOG that offered very expensive services, such as database searches via modem. That could be expensive. You had a fee for the phone. Then you might have a per-minute charge for the phone call, especially if the computer was in another city. Then you had to pay the service provider, which could be very expensive.

Even before the consumer Internet, this wasn’t workable. Tymnet and Telenet were two services that had the answer. They maintained banks of modems practically everywhere. You dialed a local number, which was probably a “free” call included in your monthly bill, and then used a simple command to connect to a remote computer of your choice. There were other competitors, including CompuServe, which would become a major force in the fledgling consumer market.

While some local internet service providers (ISPs) had their own modem banks, when you saw the rise of national ISPs, they were riding on one of several nationwide modem systems and paying by the minute for the privilege. Eventually, some ISPs reached the scale that made dedicated modem banks worthwhile. This made it easier to offer flat-rate pricing, and the presumed likelihood of everyone dialing in at once made it possible to oversubscribe any given number of modems.

The Cost

Once consumer services like CompuServe, The Source, and AOL started operations, the cost was less, but still not inexpensive. Some early services charged higher rates during business hours, for example. There was also the cost of a phone line, and if you didn’t want to tie up your home phone, you needed a second line dedicated to the modem. It all added up.

By the late 1990s, a dial-up provider might cost you $25 a month or less, not counting your phone line. That’s about $60 in today’s money, just for reference. But the Internet was also booming as a place to sell advertising.

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This is an image that would have been difficult to chroma key by hand.

CorridorKey Is What You Get When Artists Make AI Tools

March 18, 2026 by 12 Comments

You may not have noticed, but so-called “artificial intelligence” is slightly controversial in the arts world. Illustrators, graphics artists, visual effects (VFX) professionals — anybody who pushes pixels around are the sort of people you’d expect to hate and fear the machines that trained on stolen work to replace them. So, when we heard in a recent video that [Niko] of Corridor Digital had released an AI VFX tool, we were interested. What does it look like when the artist is the one coding the AI?

It looks amazing, both visually and conceptually. Conceptually, because it takes one of the most annoying parts of the VFX pipeline — cleaning up chroma key footage — and automates it so the artists in front of the screen can get to the fun parts of the job. That’s exactly what a tool should do: not do the job for them, but enable them to enjoy doing it, or do it better. It looks amazing visually, because as you can see in the embedded video, it works very, very well.

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A blue frontplate to a circuit board is shown. On the left side is an OLED screen displaying "4.35 µH". To the right of this are a red and a black socket, with an inductor between them.

Building An LC Meter With A Franklin Oscillator

March 18, 2026 by 3 Comments

Although it dates back to the early days of the Marconi Company in the 1920s, the Franklin oscillator has remained a relatively obscure circuit, its memory mostly kept alive by ham radio operators who prize its high stability at higher frequencies. At the core of the circuit is an LC tank circuit, a fact which [nobcha] used to build quite a precise LC meter.

The meter is built around two parts: the Franklin oscillator, which resonates at a frequency defined by its inductance and capacitance, and an Arduino which counts the frequency of the signal. In operation, the Arduino measures the frequency of the original LC circuit, then measures again after another element (capacitor or inductor) has been added to the circuit. By measuring how much the resonant frequency changes, it’s possible to determine the value of the new element.

Before operation, the meter must be calibrated with a known reference capacitor to determine the values of the base LC circuit. In one iteration of the design, this was done automatically using a relay, while in a later version a manual switch connects the reference capacitor. Because the meter measures frequency differences and not absolute values, it minimizes parasitic effects. In testing, it was capable of measuring inductances as low as 0.1 µH.

We’ve seen a few homebrew LC meters here, some battery-powered and some rather professional.

Testing Whether Heated Chambers Help Brittle Filaments

March 17, 2026 by 3 Comments

Some FDM filaments are pretty brittle even if properly dried and stored, especially those which contain carbon fiber (CF) or similar additives like glass fiber (GF). This poses a problem in that these filaments can snap even within the PTFE tube as they’re being guided towards the extruder. Here a community theory is that having an actively heated chamber can help prevent this scenario, but is it actually true? [Dr. Igor Gaspar] of the My Tech Fun YouTube channel gave this myth a try to either confirm or bust it.

The comments suggested that heating the chamber to 65°C will help, but there’s little information online to support this theorem. To test the claim, a heated chamber was used along with a bending rig to see at which angle the filament would snap. In total five different filaments from three manufacturers (Polymaker, Qidi and YXPolyer) were tested, including Qidi’s PET-GF and PAHT-GF as the sole non-CF filaments.

A big question is how long exactly the filament will spend inside the heated chamber after making its way from the spool, which would be about 2.5 minutes with a 500 mm tube. For the test 5 minutes was used for the best possible result. Despite this, the results show that even with the standard deviation kept in mind, the heating actually seems to make the filaments even more brittle.

Considering that in general CF seems to simply weaken the polymer matrix after printing, this finding adds to the question of whether these CF and GF-infused filaments make any sense at all.

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How To Grow Large Sugar Crystals

March 17, 2026 by 7 Comments

Many substances display crystallization, allowing them to keep adding to a basic shape to reach pretty humongous proportions. Although we usually tend to think of pretty stones that get fashioned into jewelry or put up for display, sugar also crystallizes and thus you can create pretty large sugar crystals. How to do this is demonstrated by [Chase] of Crystalverse fame in a recent video.

This is effectively a follow-up to a 2022 blog article in which [Chase] showed a few ways to create pretty table sugar (sucrose) based crystals. In that article the growth of single sucrose crystals was attempted, but a few additional crystals got stuck to the main crystal so that it technically wasn’t a single crystal any more.

With this new method coarse sugar is used both for seed crystals as well as for creating the syrupy liquid from mixing 100 mL of water with 225 grams of sugar. Starting a single crystal is attempted by using thin fishing wire in a small vessel with the syrup and some seed crystals, hoping that a crystal will lodge to said fishing wire.

After a few attempts this works and from there the crystals can be suspended in the large jar with syrup to let them continue growing. It’s important to cover the jar during this period, as more crystals will form in the syrup over time, requiring occasional removal of these stray ones.

Naturally this process takes a while, with a solid week required to get a sizeable crystal as in the video. After this the crystal is effectively just a very large version of the sugar crystals in that 1 kg bag from the supermarket, ergo it will dissolve again just as easily. If you want a more durable crystal that’s equally easy to grow, you can toss some vinegar and scrap copper together to create very pretty, albeit toxic, copper(II) acetate crystals.

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Zip-Drive Emulator Puts Big Disks Back On LPT

March 17, 2026 by 16 Comments

Iomega’s Zip drives filled an interesting niche back in the 1990s. A magnetic disk that was physically floppy-sized, but much larger in capacity– starting at 100 MB, and reaching 750 MB by the end–they never quite had universal appeal, but never really went away until flash memory chased them out of the marketplace in the early 2000s. While not everyone is going to miss them, some of us still think it’s a better form factor than having a USB stick awkwardly protruding from a computer, or microSD cards that are barely large enough to see with the naked eye. [Minh Danh] is one of those who still has affection for Zip drives, and when his parallel port Zip 100 drive started to give up the ghost last year, he decided to do something bold: reverse engineer it, and produce an emulator. First software, and then in hardware.

It’s not the prettiest-ever prototype, but lots of great things start with a mess of wires.

The first was to create a virtual zip drive that could run on a virtual machine and be accessed with DOS or Windows up to XP. The next task was to move that functionality onto a microcontroller to create something like a GoTek floppy emulator for LPT Zip drives that he’s calling the LPT100. Yes, Zip drives were built for ATAPI, SCSI, FireWire and USB, too, but [Minh]’s was on the parallel port and that’s what he wanted to replace, so the LPT interface is what set out to recreate.

It works, too, though took more guts than was expected– the 8-bit PIC18F4680 he started with just wasn’t up to the task. He moved up to a 32-bit PIC, the PIC32MZ2048EFH144 to be specific, which proved adaquate when testing with his Book 8088, a new DOS PC from 2023. Iomega’s official driver won’t run on an 8088, but the PALMZIP utility does and was able to transfer files, though only at the slow nibble rate due to limitations with the Book8088’s LPT hardware. Watch it in action below.

Alas, moving up to the Pocket386, it seemed the PIC just could not keep up. [Minh] says he’s thinking of moving to the faster Teensy 4.1, which sounds like a good idea. Considering the Teensy can be configured to serve as a drop-in replacement for a 68000, bit-banging the bus at 7.8 MHz, we’d think it should handle anything a parallel port can throw at it.

Thanks to [Minh Danh] for the tip!

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Testing A Soviet 1000 Volt Insulation Tester From 1985

March 17, 2026 by 7 Comments

Although the term ‘Iron Curtain’ from the Cold War brings to mind something like the Berlin Wall and its forbidding No Man’s Land, there was still active trade between the Soviet Union and the West. This included devices like the M4100/4 insulation tester that the [Three-phase] YouTube channel recently looked at, after previously poking at a 1967 USSR resistance bridge.

This particular unit dates to 1985, and comes in a rather nice-looking case that somewhat looks like bakelite. It’s rated for up to 1 gigaohm, putting out 1,000 V by using the crank handle. Because of the pristine condition of the entire unit, including seals, it was decided to not look at the internals but only test its functionality.

After running through the basic usage of the insulation tester it’s hooked up to a range of testing devices, which shows that it seems to be mostly still in working condition. The first issue noticed was that the crank handle-based generator was a bit tired, so that it never quite hit the maximum voltage.

With no parallax correction and no known last calibration date, it still measured to about 10% of the actual value in some tests initially, but in later tests it was significantly off from the expected value. At this point the device was suspected of being faulty, but it defied being easily opened, so any repair will have to be put off for now. That said, it being in such good condition raises the prospect of it being an easy repair, hopefully in an upcoming video.

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