OctoPrint is a useful tool for 3D printers, providing remote access to essentially every 3D printer with a USB port. [Allie Katz] decided to build an OctoPrint server in the shape of a life-sized BMO from Adventure Time, and the results are cute as heck.
A Raspberry Pi 4 is the heart of the build, with [Allie] selecting a 8 GB model for the job. It’s paired with a Raspberry Pi touchscreen that serves as BMO’s face. The Pi is also given a stereo audio output board, and hooked up to a custom PCB that runs all of BMO’s buttons. Printing BMO itself was fairly straightforward, but requires some experience working with larger PETG parts. A useful note for those playing along at home is that Polymaker PolyLite PETG in teal is just about a perfect dupe for BMO’s authentic body color.
A bit of Python code animates BMO’s face and delivers funny quips at the press of a button. When it’s time to work, though, the touchscreen serves as a straightforward interface for OctoPrint. The resulting build is both fun and functional, and a great example of what 3D printing really can achieve. It’s a cute figurine and a functional print all in one, something we don’t see everyday!
We know. The title sounds like a bad newsreel from 1942. Turns out, though, that the Nazis were really good at pouring money into military research and developing — or trying to develop — what they called “wunderwaffe” — wonder weapons. While we think of rockets and jets today as reasonably commonplace, they were state-of-the-art when Germany deployed them during WWII. While the rockets were reasonably successful, the jets were too few and too late to matter. However, those were just the tip of the iceberg. The German war industry had plenty of plans ranging from giant construction to secret weapons that seem to be out of the pages of a pulp science fiction magazine.
Size Matters
Part of the plans included huge ships including one aircraft carrier displacing 56,500 tons. Many of these were never completed and, in some cases, were never actually started. In contrast, the Essex-class USS Hornet displaces 31,300 tons and the Lexington was 37,000 tons. The H-class battleships would have had as much as 140,000 tons of displacement dwarfing the Yamato class (73,000 tons) and the Iowa class (53,000 tons).
Hackaday Editor-in-Chief Elliot Williams took time out from Supercon planning to join Staff Writer Dan Maloney for a look through the hacking week that was. We always try to keep things light, but it’s hard sometimes, especially when we have to talk about wars past and present and the ordnance they leave behind. It’s also not a lot of fun to talk about a continent-wide radio outage thanks to our angry Sun, nor is learning that a wafer-thin card skimmer could be lurking in your ATM machine.
But then again, we did manage to have some fun by weighing cats to make sure they’re properly fed, and making music by pegging VU meters. We also saw how to use PCBs to make a beautiful yet functional circuit sculpture, clean up indoor air on a budget, and move microns with hardware store parts. And we also got to celebrate a ray of international hope by looking back on the year that taught us much of what we know about the Earth.
Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!
Texas Instruments isn’t the name you usually hear associated with the first microprocessor. But the TI TMX 1795 was an 8008 chip produced months before the 8008. It was never available commercially, though, so it has been largely forgotten by most people. But not [Ken Shirriff]. You can see a demo from 2015 of the device in the video below, too.
The reason the chips have the same architecture is they were built to replace the same large circuit board inside a Datapoint 2200 programmable terminal. These were big beasts that could be programmed in BASIC or PL/B.
Datapoint asked Intel to shrink the board to a chip due to heating problems — but after delays, they instead replaced the power supply and lost interest in the device. TI heard about the affair and wanted in on the deal. However, Datapoint was unimpressed. The chip didn’t tolerate voltage fluctuations very well, since they had replaced the power supply and had a new CPU design that was faster than the chip would be. They were also unimpressed with how much stuff you had to add to get a complete system.
So why did the Intel 8008 work out in the marketplace but the TI chip didn’t? After all, Datapoint decided not to use the 8008, also. But as [Ken] points out, the 8008 was much smaller than the TI chip and, thus, was more cost-effective to produce.
As usual, [Ken]’s posts are always interesting and enlightening. He’s looked at a lot of old computers. He’s even dug into old space hardware. Great stuff!
I got a rude awakening Wednesday morning this week. HaD writers don’t necessarily keep normal hours — don’t judge. A local client called, complaining that Google Maps was blocking on one of their computers, and the browser stated that it was a malicious site. Well that got my attention. Standard incident response: “Turn off the affected computers, I’m on my way.” Turns out, it was Malwarebytes that was complaining and blocking Google Maps, as well as multiple other Google domains. That particular machine happened to have a fresh install of the program, and was still in the trial period of Malwarebytes premium, which includes the malicious IP and domain blocking feature.
Oof, this could be bad. The first possibility that came to mind was a DNS hijack. The desktop’s DNS was set to the router, and the router’s DNS was set to the ISP’s. Maybe the ISP had their DNS servers compromised? Out came the cell phone, disconnected from the WiFi, for DNS lookups on some Google domains. Because Google operates at such a massive scale, they have multiple IPs serving each domain, but since the two different results were coming from the same subnet, the suspicious DNS server was likely OK. A whois on the blocked IP also confirmed that it was a Google-owned address. We were running out of explanations, and as a certain fictional detective was known for saying, “whatever remains, however improbable, must be the truth.” And, yes, Malwarebytes did indeed accidentally add Google to its bad list. The upside was that my customer wasn’t compromised. The downside? I had to answer a phone call before my first cup of coffee. Blegh.
With an ever-growing constellation of Starlink satellites whizzing around over our heads, you might be getting the urge to start experimenting with the high-speed internet service. But at $100 or more a month plus hardware, the barrier to entry is just a little daunting for a lot of us. No worries, though — if all you’re interested in is tracking [Elon]’s birds, it’s actually a pretty simple job.
Now, we’re not claiming that you’ll be able to connect to Starlink and get internet service with this setup, of course, and neither is the delightfully named [saveitforparts]. Instead, his setup just receives the beacon signals from Starlink satellites, which is pretty interesting all by itself. The hardware consists of his “Picorder” mobile device, which sports a Raspberry Pi, a small LCD screen, and a host of sensors, including an RTL-SDR dongle. To pick up the satellite beacons, he used a dirt-cheap universal Ku-band LNB, or low-noise block downconverter. They’re normally found at the focal point of a satellite TV dish, but in this case no dish is needed — just power it up with a power injector and point it to the sky. The signals show up on the Picorder’s display in waterfall mode; curiously, the waterfall traces look quite similar to the patterns the satellites make in the night sky, much to the consternation of astronomers.
Of course, you don’t have to have a Picorder to snoop in on Starlink — any laptop and SDR should work, despite [saveitforparts]’ trouble in doing so. You shouldn’t have much trouble replicating the results by following the video below, which also has a few tips on powering an LNB for portable operations.
When [Stephen Cass] found himself with a broken Tandy TRS-80 Model 100 portable computer, the simplest solution was to buy another broken one and make one working computer from two non-working computers. However, this left him with a dilemma — what to do with the (now even more) broken one left over?
LCD layout is unusual by modern standard, but optimized for fast updates
Luckily, the Model 100 has a substantial fanbase and there’s a lot of helpful information available online, including the detailed service manual, that helped [Stephen] to understand how to drive the unusual display. The LCD has a resolution of 240×64 pixels, which are broken down into eight zones of 50×32 pixels, and two zones of 40×42 pixels. Each zone is then further divided into four banks, eight pixels tall, so that each column of eight pixels corresponds to a single byte.
Every one of the ten zones is controlled by an individual HD44102 driver IC, connected to a 30-bit wide bus for selecting the correct chip, bank and column.
With the Arduino handling the data, the old LCD still needed a -5 V supply for contrast and an RC filter to smooth out the PWM signal [Stephen] is using to adjust the viewing angle.
With the new interface, [Stephen] is able to access all of the pixels on the original display, and to use modern graphics libraries such as displayio. With the display issue solved, he intends to use a separate Teensy 4.1 to connect with the keyboard matrix and provide a VT100 terminal interface.
Schematic of the HD44102 driver circuit
Upcycling old, broken hardware can be a lot of fun and is always educational. Understanding why certain design decisions were made at a time when the engineering trade-offs were different can lead to insights that are directly relevant to modern designs when resources get tight. In this case, the quirky LCD drivers were a response to making the display of text as efficient as possible, so as not to overburden the processor.
The TRS-80 computers are ripe for hacking, with their “built-for-service” designs, and we’ve featured a few in the past. Some have replaced the motherboard with something newer, like [Stephen], whereas others have also replaced the display, or connected them to the cellphone network.
Have you found new ways to get old hardware working? Tell us in the comments below or send us a message on the Hackaday tips line.
