Before LEGO train sets moved to battery-powered locomotives with plastic rails, all of them worked pretty much like any other train set of the era. This meant metal rails that the locomotive’s wheels would use to pick up power from and a central controller that would inject said power and also regulate the train’s speed and direction. The LEGO 2868b Electric Train Speed Regulator is one such example, and [Nonsense Wars] recently had one under the knife to repair it.

The single PCB inside is quite straightforward, with the 9-12 VAC supply input from an external power adapter, and a variable voltage regulator that sees its target voltage switched by a bank of resistors.

It are these resistors that the big yellow control switches between when you operate it, changing the output voltage and also output polarity you cross the midway point. Effectively this means that there is just one non-passive component on the PCB, in the form of the TO-220 package strapped to the big heatsink.

In this particular unit it was found to be a Fairchild KA317, which is for all intents and purposes here the same as an LM317T. One quick swap later and this controller was back in business like it was 1995.

Compared to the engineering crammed into a modern “smart brick”, things really have come quite a ways in the world of LEGO.

As children, many of us looked wistfully into the cockpits of heavy machinery, wondering just how the series of knobs and levers would do something like operate a bulldozer, crane, or excavator. The nature of these myriad of hydraulic and electronic controls for equipment like this is often inscrutable to adults as well; it takes a considerable amount of training to be able to competently operate most of these machines. But this new controller from MIT may help shorten that training time.

The controller is specifically meant for excavators. In a standard excavator, a pair of joysticks is typically used, with one controlling the swing and the boom and the other controlling the stick and the bucket. Getting used to this combination can take practice, so instead the group of researchers replaced them with a model excavator arm that the operator controls directly with their own arm. The new controller is more intuitive to use as it translates the movements of the model to that of either a real excavator or a training simulation.

The researchers plan to include haptic feedback in future versions, which will hopefully further increase the ease of which new operators can get a feel for using these machines. For those not working towards a new career or an ambitious weekend with rental equipment, there are some other ways of learning how to operate excavators and other pieces of heavy machinery.

The Steam Controller is a device capable of many interesting feats. It’s intended to act simply as an input device, and yet, it can run games all on its own. As [Owen Feldman] has demonstrated, by having the Steam Controller play Zork.

[Owen] took quite an interesting route to get the there: he wrote a Rust program to emulate the Intel 8080 CPU and CP/M, as one does. This was ported to the Steam Controller, which emulates the CPU and memory on its own internal processor. I/O is streamed over USB, since the Steam Controller lacks a keyboard or screen. The CP/M disk lives in the controller, but the Zork disk data is streamed over USB as well.

If you’re wondering how [Owen] got all this running on the controller, he explains on his personal website. He used what appears to be an undocumented tool included with Steam that allows flashing firmware on the device. Helpfully, Valve also include the original firmware in the same folder, unsigned and only relying on a simple CRC checksum. [Owen] bricked his controller a couple times experimenting with this tool and loading his own firmware, but all came good in the end.

The Steam Controller is probably the oddest device to run CP/M for a while, but hey—it’s a neat party trick. Not much is going to top the auto-docking hack from a few months ago, though.

Someone reportedly paid $200 for a mystery Xbox controller on OfferUp, and the apparent Microsoft prototype could be an early Elite Series 3 complete with a tiny built-in display.