4 ms·

They sold books of codes in addition to the hardware.

• VyseofArcadia 4y ago
  I bought some as a kid, and the real value wasn't additional codes for games already covered, but codes for new games that didn't have any yet. I would have felt pretty ripped off if I had spent what little money I could get on the newest Super Mario Bros. 3 codes only to discover it was six extra lives when I already had a code for three.
• delecti 4y ago
  At least some of those code books also included instructions for that kind of experimentation though. I very clearly remember my dad using those instructions to change Mario's jump height in SMB1 to just bypass whole levels by modifying the existing jump height codes.