In the 1967 movie The Graduate, a wise older man gives some advice to the title character: plastics. Indeed, plastics would become big business. In 1962, though, a computer-savvy character might have offered a different word: transfluxor. What’s a transfluxor? Well, according to computer history sleuth [Ken Shirriff], it was the heart of a 20-pound transistor computer from Arma. Of course, plastics turned out to be a better bet, but in 1962, the transfluxor seemed to be the wave of the future.
In 1962, most computers were room-sized, but the Arma was “micro” taking up just 0.4 cubic feet — less than an Apple II. It would eventually spawn computers used in ships at sea and airplanes ranging from the Concorde to Air Force One.
We’ve seen quite a few DIY 2G networks over the years, but the 4G field has been relatively barren. Turns out, there’s an open source suite called srsRAN that lets you use an SDR for setting up an LTE network, and recently, we’ve found a blog post from [MaFrance351] (Google Translate) that teaches you everything you could need to know if you ever wanted to launch a LTE network for your personal research purposes.
For a start, you want a reasonably powerful computer, a transmit-capable full-duplex software defined radio (SDR), suitable antennas, some programmable SIM cards, and a few other bits and pieces like SIM card programmers and LTE-capable smartphones for testing purposes. Get your hardware ready and strap in, as [MaFrance351] guides you through setting up your own base station, with extreme amounts of detail outlining anything you could get caught up on.
For a while around a quarter century ago PC motherboards came with a special slot, a little shorter than the PCI slots which ruled the roost back then, and offset from them further into the case. This was the Accelerated Graphics Port, or AGP, a standard created to more quickly serve the 3D graphics cards which were then taking the world by storm. It was everywhere for a few years, then in the mid-2000s it was replaced by PCI Express and faded into obscurity. [Peter] has a Socket 7-based NAS with an AGP slot, and was left wondering whether the unused port could be put to a worthwhile purpose.
AGP is a superset of PCI clocked at 66 MHz, and usually benefiting from having its own exclusive bridge to the processor bus. Thus he reasoned that he could make an AGP to PCI adapter and it might work, as the right connections are all there. A hacked-together version was made by butchering two riser cards, and when a network card worked quite happily he knew he was on to something and made a PCB. There’s a caveat that it only works with 66-MHz capable PCI cards so not everything will work, but if you’re one of the very few people who must be in the market for one, he can do you a PCB.
Concluding a four-part repair-a-thon on a stack of Cybiko handheld computers, [Robert] over at Robert’s Retrocovered the intricate details of fixing a last batch of four in a nearly one-hour long video. These devices, with their colorful transparent cases, are a great time capsule of the early 2000s. Even with their limited hardware, they provided PDA-like capabilities to teens years before smartphones were a thing, with features including music playback and wireless chat (albeit limited to recipients within 100 meters).
Of the four units covered in this video, they are all the original Cybiko Classic, with two each of the first and second revision, none of which were booting due to a bad Flash chip. Another issue was the dead rumble motors on them, which fortunately are the easiest to replace. One of the units also has a dead display, which did not get replaced this time around.
Insides of a Cybiko Classic (Credit: Robert’s Retro, YouTube)
The flash chip replacement was a bit more of a headache, as these devices don’t just take any chip, mostly due to how much the system relies on the ready-busy line. This led [Robert] to replace the old 4 Mb AT45DB041 chips with the 16 Mb Atmel AT45DB161. Previously he had taken 1 MB chips from an expansion cartridge to replace more dead flash chips, so those were replaced with 2 MB chips.
With fresh flash in place, the next challenge was to get these written with a firmware image, with the v2 Cybiko units already having CyOS on the separate 256 kB Flash chip, but the v1 units relying on the single big Flash chip for all storage. Fortunately, an enterprising member of the community developed a tool to ease this ordeal by allowing a Cybiko unit in its serial dock to be flashed with no issues, other than the 2 MB Flash causing some issues as this was a previously unknown hardware configuration.
[Robert] now has four working Cybiko units, with one being headless due to the busted screen, and more room for apps on the 2 MB units than a 2000s teenager would have known what to do with.
Hacks are rough around the edges by their nature, so we love it when we get updates from makers about how they’ve improved their process. [Denny] from Shake the Future has just provided an update on his microwave casting process.
Sticking metal in a microwave certainly seems like it would be a bad idea at first, but with the right equipment it can work quite nicely to develop a compact foundry. [Denny] walks us through the process start to finish in this video, including how to build the kilns, what materials to use, and how he made several different investment castings using the process. The video might be worth watching just for all the 3D printed tools he’s built to aid in the process — it’s a great example of useful 3D prints to accompany your fleet of little plastic boats.
A lot of the magic happens with a one minute on and six minutes off cycle set by a simple plug timer. This allows a more gradual ramp to burn out the PLA or resin than running the microwave at full blast which can cause some issues with the kiln, although nothing catastrophic as demonstrated. Vacuum is applied to the mold with a silicone sleeve cut from a swimming cap while pouring the molten metal into the mold to draw the metal into the cavities and reduce imperfections.
We appreciate the shout out to respirators while casting or cutting the ceramic fiber mat. Given boric acid’s effects, [PDF] you might want to use safety equipment when handling it as well or just use water as that seems like a valid option.
[Birdbrain] is trying to make their own microfluidic devices. To aid in this quest, they need a quality microscope to see what they’re doing. Instead of buying one outright, they purchased a cheap microscope and upgraded it to do the job instead.
Usability and performance is greatly improved over the stock unit, which was really only fit for learning purposes.
The cheap education-grade microscope cost around $50 USD, had few features, and wasn’t much chop out of the box. The worst part was the sample stage — which was poorly adjustable in the up-and-down axis and could only track about two centimeters up and down. There was no X or Y axis panning either, and it lacked a proper condensor iris, too. Oh, and the included camera module had a resolution of just 240p.
To fix these problems, the microscope was first outfitted with a fully redesigned X-Y-Z stage built out of old components from a salvaged DVD drive and an additional NEMA stepper motor. Camera-wise, it was hooked up with a 2K Raspberry Pi Camera Module 3 running at 10 to 15 frames per second, which broadcasts video over a local network for easy viewing on an external monitor. It also gained an epi-illumination setup for doing reflected light microscopy.
Original retrocomputing hardware is now decades old and showing its age, so the chances are it’s more common in 2024 to experience a machine from the 1970s or 1980s by way of an emulator on a modern machine than it is on the real hardware. There’s another more limited emulation scene as similar 8-bit machines emulate each other, for example when the very similar Dragon 32 and Tandy CoCo have a go at each other’s software. Rarest of them all though is when one classic machine emulates another with a different architecture, but that’s exactly what’s happened with [DragonBytes], who has persuaded a Tandy CoCo to emulate an Apple II.
The two machines have significant hardware differences, but we’re guessing that the project is helped a little by the Motorola 6809 in the CoCo and the MOS 6502 in the Apple having both in a sense been different visions of a successor to the Motorola 6800. Thus their architectures while different, are not diametrically opposed. The other hardware is certainly not so similar though, with Moto’s 6847 display chip in the Tandy being far more conventional than Steve Wozniak’s clever NTSC hacks to achieve a color display for minimal cost on the Apple.
The project is written in assembler, and doesn’t by any means claim to support all Apple modes, or be cycle accurate. But it’s a hugely impressive achievement nevertheless.
