A Byte of Coding Issue 353

Hello,

Hope you all had a nice weekend. Here’s the issue.

Reverse-engineering an analog Bendix air data computer: part 4, the Mach section

Published: 11 February 2024

Tags: reverse engineering, hardware, history

Ken Shirriff dissects “the Bendix Central Air Data Computer (CADC)”, which was used “to compute airspeed, Mach number, and other ‘air data’” in fighter planes from the 1950s.

Some highlights:

• “Aircraft have determined airspeed from air pressure for over a century", by determining the ratio of air pressure between the “static” pressure and the air pressure created by the outside air being pushed into a tube

• all calculations are done via mechanical means, using gears and cams

• “The CADC performs nonlinear calculations that seem way too complicated to solve with mechanical gearing”

ActivityPub Server in a Single PHP File

Published: 18 February 2024

Tags: php, architecture

Terence Eden implemented a Fediverse server in one php file.

Some highlights:

• outlines the criteria for the design

• walks through the different parts of the server

• mostly useful as an educational tool

End-to-end testing emails

Published: 16 February 2024

Tags: javascript, testing

Wesley Aptekar-Cassels demonstrates a simple method for testing email sending / receiving, using nodejs.

Some highlights:

• uses a SMTP and HTTP server

• 39 lines of javascript

• some tips on using playwright for end-to-end testing for web apps