This sure takes me back to hand-coding embedded systems firmware for a family of products on Microchip 8-bit microcontrollers... and that was as recent as this

This sure takes me back to hand-coding embedded systems firmware for a family of products on Microchip 8-bit microcontrollers... and that was as recent as this millennium. In the days before ARM and when we needed to use a $3 processor to hit our BOM cost, my code used every byte of the 8K and every register... bit-banged I2C, bit-banged RS232 up to 56Khz, LED and 8-key touchpad debouncing, and best of all, an IR receiver and IR emitter which both learned arbitrary consumer IR codes in the fashion of a then-fashionable universal remote, and reproduced them including press-and-hold behavior, while emulating their carrier frequency... and could do bi-directional device cloning via IR by holding the products up to one another face-to-face... And had a rock-solid bootloader for encrypted firmware updates. Ah the good ol' days... a tear for the old skool. I called the binder with the hard copy of the commented assembler source "my first novel"...