Bloxeed (System C)
Bloxeed is an arcade Tetris variant with some interesting gimmicks. Whereas the System 18 version was Japan-only, the System C version was released worldwide.
Since the System C version of the game doesn't use any ROM encryption, it instead has an anti-piracy scheme that the System 18 version doesn't.
After starting a new game, the game will start checking every frame to make sure that the words "TETRIS" and "SEGA" on the copyright screen haven't been modified. If either one has, the game will deliberately crash.
There's a strange message at $C754 (World set) / $C776 (US set):
FOR COPY BOARD MAKER KISS RUSSIAN'S ASS!!
There's a hard tab between RUSSIAN'S and ASS instead of a space for some reason. The older System 18 version doesn't have this message.
To see these in the ROM, you'll need to interleave the two 68000 program ROMs in the MAME bloxeedc or bloxeedu ROM sets; use the IC32 ROM for even bytes and IC31 for odd. Use Neil Corlett's byteshuf utility if you're not sure what to use. This version of the game doesn't use any encryption whatsoever, unlike its System 18 predecessor.
It's possible that this text was originally meant to be displayed as part of the aforementioned anti-piracy; "FOR COPY BOARD MAKER" is the exact length of the line "FOR COIN-OP MACHINES" that normally appears on the copyright screen.
Name Entry Miscellanea
There are various secret names you can enter when you get a high score:
- Enter a high score name of "KEN"; your slot and the next one will become "MIC" and "LUV", respectively.
- Enter a high score name of "SEX"; your slot and the next one will become "OH!" and " NO", respectively. (The " NO" contains an initial space.)
- Enter a high score name of "MOR"; your slot and the next two will become "YAM", "AGI", and "WA!", respectively.
- If you enter no name (just scroll to END and press the button), the game will fill your name with "NOP".
The subroutine handling the detection of these names is located at $BE90.
In the service menu, if you hold down the Service 1 button (the "9" key, not number pad, in MAME; it adds a credit outside the service menu), Player 1 Down, and Player 2 Right simultaneously as you press the Service button (F2 in MAME), and KEEP THOSE THREE BUTTONS HELD DOWN (release them, and the checksum display won't be complete), you'll see the actual checksum of the various memory chips along with information telling you if the check was successful.
The checksum is shown as four four-digit hexadecimal numbers; the checksum it checks against is stored at $3F0 as 4 words (8 bytes).