Space Invaders '95: The Attack of Lunar Loonies

Taito's take on the self-spoofing style done in Konami's Parodius series.

Debug Functions#

Crash Handler#

This game has a basic exception handler for the standard set of exception vectors. It prints data for the program counter, status register, fifteen of the sixteen data/address registers, and the stack pointer at the point of exception.

Level Select#

This game uses the Taito Code:

1. Hold the Service Coin button upon booting, and wait until a "SERVICE SWITCH ERROR" message pops up on the screen.
2. Press 1P Start (×3), Service Coin, 1P Start.

If successful, a stage select menu will appear, which can be navigated with the 1P Joystick. Additionally, upon selecting a stage, the player gains 9 credits.

Expanded Input Test#

Normal	Full

Entering the Taito Code on the switch test will greatly expand the number of inputs tested to include every possible input that the F3 system supports.

Running Debug#

Put the following two codes in MAME's spcinv95.xml cheat file to enable a Tilt-triggered debug menu.

  <cheat desc="Ignore Checksum">
    <script state="run">
      <action>maincpu.mw@000FDA=0x0002</action>
    </script>
    <script state="off">
      <action>maincpu.mw@000FDA=0x00AE</action>
    </script>
  </cheat>

  <cheat desc="Tilt Debug">
    <script state="run">
      <action>maincpu.md@000780=0x4EB90001</action>
      <action>maincpu.md@000784=0xEB844E75</action>
    </script>
    <script state="off">
      <action>maincpu.md@000780=0x4A390041</action>
      <action>maincpu.md@000784=0x55BA67EC</action>
    </script>
  </cheat>

It's a Joke#

Exits the menu.

Appear#

Brings up a prompt in the lower-left corner. The user picks which object to spawn with 1P Up/Down and spawns that object by pressing 1P Button 1.

No Hit#

When toggled, getting hit by an enemy shot or colliding with an enemy won't kill the player.

Reset#

Resets the game. Makes sense.

Otamesi SCR#

Displays the raw contents of the game's foreground and background graphics ROMs.

Controls

• 1P Up/Down: Scrolls through tiles (1 row per frame).
• 1P Left/Right: Adjusts the width of each row of tiles.
• 1P Button 1 / 1P Button 2: Adjusts palette number.
• 1P Button 3 + 1P Left/Right: Scrolls through tiles (1 screen per frame).

Otamesi OBJ#

Displays the raw contents of the game's sprite graphics ROMs.

Controls

• 1P Up/Down: Scrolls through tiles (1 row per frame).
• 1P Left/Right: Adjusts the width of each row of tiles.
• 1P Button 1 / 1P Button 2: Adjusts palette number.
• 1P Button 3 + 1P Left/Right: Scrolls through tiles (1 screen per frame).

Otamesi OBJTBL#

Displays properly assembled sprites from the game's sprite table.

Controls

• 1P Up/Down: Adjusts sprite number by 01 per frame).
• 1P Left/Right: Toggles horizontal and vertical flip bits.
• 1P Button 1 / 1P Button 2: Adjusts palette number.
• 1P Button 3 + 1P Left/Right: Adjusts sprite number by 10 per frame.
• 2P Joystick: Repositions the sprite.

Carnage / Mongol#

Both options destroy all on-screen enemies. "Carnage" jumps to a subroutine (0x01EC5E) that just jumps to an enemy-clearing subroutine (0x00503C) and exits, while "Mongol" jumps to 0x00503C directly.

Regional Differences#

International	US

On the Continue screen, non-US sets have a referee-like creature that points his finger down in rhythm with the countdown. The US sets instead have Taito's typical Continue instructions in its place.

References#