Tiny Computers from Texas: The Early History of the Microcontroller
thechipletter.substack.com
thechipletter.substack.com
I think programming a microcontroller without an operating system is a good exercise for most coders / software engineers. It gives you a perspective of how much you can accomplish using MMIO and an imperative programming language. (C, C++, Rust generally).
These days, microcontrollers span a range of price points and capabilities. (CPU speed, flash, RAM, onboard peripherals etc). There are even <$1 32-bit ones (See STM32C0), and ones that cost $10-20 and have 2MB of flash run at 500Mhz, have 64-bit FPUs, loads of hardware IO protocols and ADC/DAC channels etc. Also some that are ~$3USD and have onboard Wi-Fi, Btle, LoRa etc, and can run for years on small batteries.
One wonders what impact the LFSR would have on the processor cache architecture, since there is spatial locality is not preserved. There is also a potential to run the program in reverse.