Ethernet For Hackers: Equipment Exploration

February 28, 2024 by 28 Comments

Last time, we talked about the surface-level details of Ethernet. They are fundamental to know for Ethernet hacking, but they’re also easy to pick up from bits and pieces online, or just from wiring up a few computers in your home network. Now, there’s also a bunch of equipment and standards that you will want to use with Ethernet – easy to find whether used or new, and typically as easy to work with. Let’s give you a few beacons!

Routers And Switches

Whenever you see a box with a few Ethernet ports, it’s either referred to as a router, or a switch, sometimes people will even use the word “hub”! Fortunately, it’s simpler than it may seem. A router is a smart device, typically with an OS, that ties two or more networks together – routing packers from one network to another, and typically taking care of things like handing out local IP addresses via DHCP. A switch merely helps Ethernet devices exchange packets between each other on the same level – it’s typically nowhere near as smart as a router gets. Oftentimes, a home router will contain a switch inside, so that you can plug in multiple of your home devices at once. That’s the main difference – a switch merely transmits packets between Ethernet-connected devices, while a router is a small computer taking care of packet forwarding between networks and possibly including an Ethernet switch on the side.
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MovieCart Plays Videos On The Atari 2600

February 23, 2024 by 12 Comments

The original Xbox and PlayStation 2 both let you watch DVD movies in addition to playing games. Seldom few consoles before or since offered much in the way of media, least of all the Atari 2600, which was too weedy to even imagine such feats. And yet, as covered by TechEBlog, [Lodef Mode] built a cartridge that lets it play video.

It’s pretty poor quality video, but it is video! The MovieCart, as it is known, is able to play footage at 80×192 resolution, with a color palette limited by the capabilities of the Atari 2600 hardware. It’s not some sneaky video pass-through, either—the Atari really is processing the frames.

To play a video using the MovieCart, you first have to prepare it using a special utility that converts video into the right format for the cart. The generated video file is then loaded on a microSD card which is then inserted into the MovieCart. All you then have to do is put the MovieCart into the Atari’s cartridge slot and boot it up.  Sound is present too, in a pleasingly lo-fi quality. Control of picture brightness and sound volume is via joystick. You could genuinely watch a movie this way if you really wanted to. I’d put on House of Gucci.

Thanks to the prodigious storage available on microSD cards, you can actually play a whole feature length movie on the hardware this way. You can order a MovieCart of your very own from Tindie, and it even comes with a public domain copy of Night of the Living Dead preloaded on a microSD card.

We don’t see a big market for Atari 2600 movies, but it’s neat to see it done. Somehow it reminds us of the hacked HitClips carts from a while ago. Video after the break.

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PC AT mainboard with both 16-bit ISA and 32-bit PCI slots. (Credit: htomari, Flickr)

How Intel Gave Us The PCI Bus While Burying VESA’s VL-Bus

February 15, 2024 by 39 Comments
Gigabyte GA486IM mainboard from 1994 with ISA, VLB and PCI slots. (Credit: Rjluna2, Wikimedia)
Gigabyte GA486IM mainboard from 1994 with ISA, VLB and PCI slots. (Credit: Rjluna2, Wikimedia)

The early days of home computing were quite a jungle of different standards and convoluted solutions to make one piece of hardware work on as many different platforms as possible. IBM’s PC was an unexpected shift here, as with its expansion card-based system (retroactively called the ISA bus) it inspired a new evolution in computers. Of course, by the early 1990s the ISA bus couldn’t keep up with hardware demands, and a successor was needed. Many expected this to be VESA’s VLB, but as [Ernie Smith] regales us in a recent article in Tedium, Intel came out of left field with its PCI standard after initially backing VLB.

IBM, of course, wanted to see its own proprietary MCA standard used, while VLB was an open standard. One big issue with VLB is that it isn’t a new bus as such, but rather an additional slot tacked onto the existing ISA bus, as it was then called. While the reasoning for PCI was sound, with it being a compact, 32-bit (also 64-bit) design with plug and play and more complex but also more powerful PCI controller, its announcement came right before VLB was supposed to be announced.

Although there was some worry that having both VLB and PCI in the market competing would be bad, ultimately few mainboards ended up supporting VLB, and VLB quietly vanished. Later on PCI was extended into the Accelerated Graphics Port (AGP) that enabled the GPU revolution of the late 90s and still coexists with its PCIe successor. We covered making your own ISA and PCI cards a while ago, which shows that although PCI is more complex than ISA, it’s still well within the reach of today’s hobbyist, unlike PCIe which ramps up the hardware requirements.

Top image: PC AT mainboard with both 16-bit ISA and 32-bit PCI slots. (Credit: htomari, Flickr)

Target Lifting Mechanism Goes Wireless

February 11, 2024 by 6 Comments

“WARNING: DO NOT Hammer on this mechanism” sounds like the start of a side quest. A quest is exactly what [CelGenStudios] started when he came upon a strange box with this message.

The military identification tag was printed “Target Holding Mechanism, M31A1”, along with some other information. It also informed the reader that the device weighed 70lbs (31.75kg). Something carrying that much mass just had to be good.

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Human-Interfacing Devices: Packing For The Descriptor Heist

February 6, 2024 by 4 Comments

We started with figuring out HID descriptors a week ago, and I’ve shown you how to send raw HID packets using a MicroPython fork. We do still have the task in front of us – making a touchscreen device. For that, let’s give you the tools to capture an existing descriptor from a touchscreen, then show you how to tweak it and how it turns out in the end.

Packing For The Heist

When it comes to this kind of adventure, we can’t go without tools and weapons – it could be dangerous! Without them, you could even abandon your project halfway! Here’s enough high-precision tools and ammunition to last you through whatever obstacles you might encounter. Except for the web-based tools, these tools are for Linux, but please remember that you can always use a virtual machine or a Raspberry Pi. Nobody would use Windows for a heist anyway, what’s with all the telemetry and such.

The first tool is for reading descriptors – we need one to learn from, it’s just like a keycard you can flash to a security guard and scan at the vault entry. Of course, with RFID, you want to have enough examples, compare bits between a few cards and all. For now, HID descriptors don’t have authenticity checks, but it looks like that might just change in the future. Leave it to Apple and Microsoft to add them, as usual. On Linux, seeing descriptors is simple – as root, go into /sys/bus/usb/devices/, find your device by its lsusb device tree path, then follow the directory with the VID/PID in it. That directory will contain a report_descriptor file – hexdump it. The entire command could look like this:

sudo hexdump -v -e '/1 "%02X "' /sys/bus/usb/devices/3-6.2/3-6.2\:1.1/0003\:0C40\:8000.0022/report_descriptor

Again, you might need root to even find this path, so use sudo -i if you must. The format string in the hexdump command gives you parser-friendly output. Specifically, for parsing, I use this webpage – it’s wonderful, even adding tabs that delineate different sections of the descriptor, making its output all that more readable! You can also save this webpage locally, it’s a very neat tool. Other than that, you can try other local tools like this one!

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They Want To Put A Telescope In A Crater On The Moon

February 6, 2024 by 30 Comments

When we first developed telescopes, we started using them on the ground. Humanity was yet to master powered flight, you see, to say nothing of going beyond into space. As technology developed, we realized that putting a telescope up on a satellite might be useful, since it would get rid of all that horrible distortion from that pesky old atmosphere. We also developed radio telescopes, when we realized there were electromagnetic signals beyond visible light that were of great interest to us.

Now, NASA’s dreaming even bigger. What if it could build a big radio telescope up on the Moon?

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Arctic Adventures With A Data General Nova II — The Equipment

February 5, 2024 by 50 Comments

As I walked into the huge high bay that was to be my part-time office for the next couple of years, I was greeted by all manner of abandoned equipment haphazardly scattered around the room. As I later learned, this place was a graveyard for old research projects, cast aside to be later gutted for parts or forgotten entirely. This was my first day on the job as a co-op student at the Georgia Tech Engineering Experiment Station (EES, since renamed to GTRI). The engineer who gave me the orientation tour that day pointed to a dusty electronic rack in one corner of the room. Steve said my job would be to bring that old minicomputer back to life. Once running, I would operate it as directed by the radar researchers and scientists in our group. Thus began a journey that resulted in an Arctic adventure two years later.

The Equipment

The computer in question was a Data General (DG) mini computer. DG was founded by former Digital Equipment Corporation (DEC) employees in the 1960s. They introduced the 16-bit Nova computer in 1969 to compete with DEC’s PDP-8. I was gawking at a fully-equipped Nova 2 system which had been introduced in 1975. This machine and its accessories occupied two full racks, with an adjacent printer and a table with a terminal and pen plotter. There was little to no documentation. Just to turn it on, I had to pester engineers until I found one who could teach me the necessary front-panel switch incantation to boot it up. Continue reading “Arctic Adventures With A Data General Nova II — The Equipment” →