NiGHTS into Dreams... on Sega Retro (segaretro.org)
Sega Mega Drive/Genesis on Sega Retro (segaretro.org)
Sega Master System on Sega Retro (segaretro.org)
TIL about the Sega Channel (segaretro.org)
“Sega Channel was a project developed by Sega for the Sega Mega Drive video game console. Completely revolutionary at the time of release (bar a failed attempt with the earlier Intellivision console), it was a method capable of streaming digital content to Mega Drive owners through cable television.”