Four short links: 4 September 2020

1. Inside the Digital Pregnancy Test — … is a paper pregnancy test and watch-battery-powered microcontroller connected to three LEDs, a photo-cell, and an LCD display. That (8-bit) microcontroller runs at 4MHz, almost as fast as an IBM PC did.
2. The Incredible Proof Machine — Fun game (modelled on The Incredible Machine from the 90s) that teaches logic.
3. Make Interfaces Hard to Misuse — Don’t push the responsibility of maintaining invariants required by your class on to its callers. Excellent advice.
4. ArangoDB — a scalable open-source multi-model database natively supporting graph, document and search. All supported data models & access patterns can be comnbined in queries allowing for maximal flexibility.

from Radar https://ift.tt/3hXFCfG