phased array

The Signal Path takes apart a Starlink dish layer by layer, analyzing the phased array RF design, system architecture and integrated circuits, with an X-ray of the RF stack.

Aaron Hsu shows how to manipulate and transform tree data in APL using arrays and inverted tables instead of pointers. He claims much smaller code, better performance and easier parallelisation.

Branch Education explains how Starlink works, from the ground dish and satellites to phased-array beam steering and data routing. Animations cover how a beam stays connected to a satellite moving at 27,000 km/h.

Aaron Hsu's FnConf18 talk asks whether APL needs a static type system. He argues that APL's expressiveness and rapid iteration already deliver the benefits usually credited to types.

Chuck Moore, inventor of Forth, presents GreenArrays' 144-core asynchronous chip at Strange Loop 2013. He explains how idle cores draw almost no power and how tight code minimizes energy use.

Andrew Kelley, creator of Zig, presents practical data-oriented design techniques for shrinking memory footprint and making programs cache friendly. He ends with a case study of how these ideas sped up the Zig compiler.

Aaron Hsu discusses design patterns and anti-patterns in APL and why the language is productive despite its write-only reputation. He argues that idioms matter more than libraries in array languages.

A 1975 live demonstration of the APL language by Imperial College professor Bob Spence, showing a REPL on a modified typewriter terminal and APL's appeal to non-programmers.

A 1974 talk-show-style interview with the original developers of APL, including Iverson, Falkoff and Breed. They discuss how the language originated.

Aaron Hsu explains why programmers often find APL harder to learn than people with no programming background. He identifies eight patterns that contrast traditional software engineering practice with APL practice, starting from Ken Iverson's language design principles.

The Thought Emporium grows living rat neurons on an electrode array and tries to train them to play Doom. It is part of a series on biological computing.

Noel Rappin's MountainWest RubyConf talk introduces Smalltalk to Ruby programmers. He compares the two languages' object models, blocks, 1-based arrays, simple syntax and live programming environment, and walks through sample code.