They sell old games, e.g. Sonic the Hedgehog: https://store.steampowered.com/app/71113/Sonic_The_Hedgehog/
That's a Windows program that runs a Sega Genesis emulator that loads the game's ROM.
In many jurisdictions (AU, UK), it would be legal to copy them to another device you own, such as a hacked PSP, under the "format shifting" exemptions.
They sell old games, e.g. Sonic the Hedgehog: https://store.steampowered.com/app/71113/Sonic_The_Hedgehog/
That's a Windows program that runs a Sega Genesis emulator that loads the game's ROM.