A deep technical exploration of Super Mario Bros. ROM coverage, attempting to execute every single byte of the game's 32,768-byte program ROM. The author documents which code paths are triggered by normal gameplay, which require deliberate manipulation (like oscillating platforms, Lakitu respawn edge cases, and enemy sprite slot tricks), and which appear to be genuinely unreachable. Key findings include: unreachable code in Lakitu's respawn fail-safe, a bug in the background-drawing routine using BMI instead of BCC that allows reading unused tile data, a two-player vine/water-level glitch that corrupts enemy data to trigger unused initialization routines, and unused character ROM tiles that store title screen drawing data. After extensive TASing and glitch exploitation, 206 program ROM bytes and 5 character ROM bytes remain unread.