Strategy X

When the world is on the line...

When all you've got is a tank, a lone soldier, and hope...

When Strategies A through W have failed...

There is always Strategy X!

Unused Graphics#

An unused sprite of a shield unit or some kind of reflector or the like. This sprite has parameters properly set up in the main CPU, but it's not in either of the game's sprite tables.

Put the following cheats in the appropriate MAME cheat file to replace the Fuel tank in Part 1 with the unused sprite:

  <cheat desc="Unused Sprite">
    <script state="run">
      <action>maincpu.mb@28B1=CF</action>
    </script>
    <script state="off">
      <action>maincpu.mb@28B1=C9</action>
    </script>
  </cheat>

  <cheat desc="Unused Sprite">
    <script state="run">
      <action>maincpu.mb@27DF=FD</action>
    </script>
    <script state="off">
      <action>maincpu.mb@27DF=F7</action>
    </script>
  </cheat>

Extra Life Value#

Like in The End, RAM 8017 (which would have been used to store the extra life score threshold) is always set to 10 on boot, but was probably planned to be set by a dip switch at one point. However, like Scramble and Super Cobra, this address is only referenced when the game has to draw the "BONUS TANK FOR XX000 PTS" text on the "PUSH START BUTTON" screen. Changing the value at 8017 will update that text but not the extra life threshold - it's hard set at 10,000 points.

Old Firing Code#

The Stern set has an older version of the game's firing code left in the ROM. This older routine lacks the auto-firing feature that the newer routine has. Note that the used code is clumsily inserted at the very end of the game data at 0x5F18, leaving the old firing code orphaned, suggesting that this was a hack that Stern put in themselves.

Put the following cheat in stratgys.xml to restore the old behavior:

  <cheat desc="Old Firing Behavior">
    <script state="run">
      <action>maincpu.mw@38B0=3D00</action>
    </script>
    <script state="off">
      <action>maincpu.mw@38B0=5F18</action>
    </script>
  </cheat>

Someone at Konami must have liked this hack, because the code was later fully integrated into one of their sets, with the old code being properly overwritten.

Version Differences#

There are two sets in MAME: stratgyx (Konami), and stratgys (Stern). The Stern set is older, with the Konami set being an updated version of Stern's. It's likely that Stern's set is based on a older undumped Konami set which used the aforementioned older firing code, though the existence of such a set is, at the time of writing, purely speculative.

Attract Mode#

Stern's demos behave like the demos seen in other Konami games like Scramble and Super Cobra: The player's movements are controlled by a single timer, which leads to poor gameplay but semi-randomizes each demo because the timer isn't cleared when the demo ends.

Konami's set changes the game's demo handler to read a set of stored inputs in the game ROMs, resulting in proper demos that better present how the game works. However, because the global timer controls enemy objects and that's still not cleared after each demo, they can and will end early if the demo ship blows up.

Stern set	Konami set

The Stern set doesn't properly clear the screen after a game demo, which leaves the Part number and a miscolored fuel gauge on the left side of the screen.

Game Start#

Stern set	Konami set

In Stern's set, the starting area is completely blank. The Konami set adds a giant arrow (which required the addition of two new tiles in the graphics ROM) with the message "GO AHEAD!!" to direct confused players on where to go.

References#