Bloxeed (System 18)

Bloxeed
Developer: Sega AM1 Publisher: Sega Platform: Arcade (Sega System 18) Released in JP: January 1990 This game has unused code. This game has a hidden developer message. This game has hidden bonus content.

A Tetris by any other name is just as addicting.

Unused Sega Intro

The System 18 version of the game contains an unused routine which displays the text "SEGA PRESENTS" one letter at a time, playing a sound effect with each letter.

This can be patched back into the unencrypted version of the game (the set titled bloxeedd in MAME) by adding the following to the ROM's cheats file (bloxeedd.xml):

  <cheat desc="Unused Intro">
    <script state="on">
      <action>temp0=maincpu.md@b222</action>
      <action>maincpu.md@b222=6000fc68</action>
    </script>
    <script state="off">
      <action>maincpu.md@b222=temp0</action>
    </script>
  </cheat>

(Source: Original TCRF research)

Developer Message

Immediately after the above "SEGA PRESENTS" text, there are two more strings that are never shown by the game:

SPECIAL THANKS TO GOD
AND EVERYONE ELSE !!

These can be seen starting at $B246 in memory, or in an unencrypted ROM after interleaving the A6 and A5 ROMs into a single file.

Name Entry Miscellanea

Enter a high score name of KEN. Your slot and the next one will become MIC and LUV, respectively.

If you enter no name (just scroll to END and press the button), the game will fill your name with NOP.

(Source: andlabs)