MicroPythonOS
Open-source operating system that runs on ESP32 boards with a touch-screen interface. Develop software in MicroPython.
How systolic arrays work
An explanation with nice diagrams and discussion of why sistolic arrays are efficient for neural networks.
Tiny Tapeout
The cheapest and easiest way to get custom silicon fabricated, as far as I can tell. The trick is not only using a shared wafer, but also sharing the chip: each design in a batch is on every chip. A controller circuit selects which design is active at a given time. See also this paper describing the history of the project.
Tayloe Quadrature Product Detector
This simple circuit directly converts from RF down to baseband. Four square waves operating at and shifted 90° from each other control a multiplexer thus producing four quadrature signals. These can be combined to give I and Q signals. A copy of the PDF is here.
I found this while reading about the Pi Pico Rx, which uses this circuit and a Raspberry Pi Pico to make a software defined radio.