INVINCIVADERS - NEW GAME

[Blue Azure]

Introducing…INVINCIVADERS…an all-new game, and yet the same old game built in. You played 99 Lives, and it's so limited (!,?). We need better. INVINCIVADERS is your new Space Invaders trainer. Never fearing dying again, you can hone your skills and revert to the original game and play better and better. INVINCIVADERS 7800 now available at your local download depot.

 

Play all 99 levels with ease and watch at about level 94 for the 6th score digit light up - 100,000 points. But wait, why is the digit one column over to the left? Was there a conflict in the code? A miscalculation? Or simply a direct port of the original arcade game? Does anyone know?

 

INVINCIVADERS FEATURES…

 

* Infinite Lives, no need for a pause button, simply leave and come back later to continue your game. Go to sleep and the Invaders will be waiting for you…dahn…dahn…dahn…dahn…dahn…dahn when you awaken.

* Starts with 3 lives just like the original game.

* Additional Life added at 1500 points just like the original game, as if you'll need it.

* Approximately 100 minutes of continuous gameplay to level 100, will you make it?

* Special bug, unintended, included…can you make it happen (In fact how do you make it happen?)? If the Invaders hit bottom when the UFO is crossing the top of the screen, the UFO waits until its shadow catches up with it and drags the UFO away. We liked it so much we left it in the game.

* Hidden code mod in the game, where it says "Game Over," it now says "Never Over." You'll never see that in game-play of course.

 

HOW IT WAS DONE…

 

First the game was disassembled so we know what happens where and when. For a 16K game, the 27128 EPROM spans from $0000-$3FFF, and when the cartridge is installed the code is mapped to $C000-$FFFF. The Game Over routine happens at $CF36 and there are two calls to it from $E379 and $E413. But we don't care about that. That's there to fool the would-be hackers! What we're looking for is "decrement lives," cuz we don't want that. To jump to a New Rack when the Invaders have landed we add a Jump at $CF36 to $CA5D, op codes 4C 5D CA. But wait, this doesn't quite work, cuz the remaining Invaders when hitting bottom stay on the screen until Bob clears them. So we must clear the screen before drawing the new rack. This is done at $E829, so we call subroutine JSR $E829 or op codes 20 29 E8. There are also jumps at $DC52 (4C 61 DC) and $DCA1 (4C B0 DC) to complete the player collision detect disable. This all happens extremely abruptly so you can see and hear the crazy effects, but that again is considered to be a feature of this new game - a direct reminder that Bob's original game was more perfect. Proper housekeeping could be done, but as a member of the Mod Squad, I assure you that we have other things to do (like disassemble the beast known as Centipede). The game title graphics were modified from Space Invaders to Invincivaders since Invincible Invaders wouldn't fit. This is done twice at $EEFE (start-up screen) and $EFOE (attract mode screen).

 

Never played the original Invisible Space Invaders? Now you can, with your EYES CLOSED.

 

I could download games all day, but what would I have learned? This is my way of giving back. What will you do? Try INVINCIVADERS today. Then tell me where in the code the Invaders, Player, & UFO bit mapping is done, so we can complete the SI Disassembly project.

 

NTSC Invincivaders - binary

SPACEINVINCIVADERS_NTSC_48A6.bin

NTSC Invincivaders - .a78

SpaceInvincivaders_NTSC_16K.a78

PAL Invincivaders - binary

SPACEINVINCIVADERS_PAL_4B7D.bin

PAL Invincivaders - .a78

SpaceInvincivaders_PAL_32K.a78

 

Happy New Year to All. 2013 is setting up to be a big year for the 7800. Can't wait.

[Stun Runner 87]

Need this on cart

[Blue Azure]

The code has been signed for encryption and ready to go. It does work, I tested it on a real machine. All you need is a blank 27128 EPROM and 16K+ EPROM board. Sorry, I don't make carts at this time. I just analyze, mod and present the code. At least you can view it on an emulator for now.