Haha, thanks for dredging this up, I made that :) It seems quite related to the OP article. It's a library for making grayscale games on the TI83 graphical calculator, which has a monochrome display. The main challenge was optimizing the interrupt routine, the z80 assembly code that performed the flickering/dithering that achieves the grayscale effect, to fit within the tiny amount of clock cycles available on the Zilog Z80 6 MHz processor. Even after optimization, it took up ~50%-75% of all available cycles. Some people managed to make some pretty fun grayscale games with it (e.g. https://www.ticalc.org/archives/files/fileinfo/331/33153.htm...). This was obviously in the pre-smartphone era, so the ti83 was quite popular for playing games in class, and hand written assembly code was the only way to make it fast.