This led [grubbycoder] down the path of porting Sonic 2 for the Sega Master System (to the eZ80-based Ti 84+ CE. Selecting this particular graphing calculator came down to the raw specs matching ...

The gold standard for graphing calculators, at least in the US, are the Texas Instruments TI-84 series ... from custom TI games that trick the two-tone display into grayscale to Game Boy emulators ...