Cosmic Ark (add'l creatures)

[Nukey Shay]

(Supercharger-compatable)

 

The original game has 7 creatures...7 more added. You may recognise some of them

Edited April 3, 2008 by Nukey Shay

[uosipa llamxew]

I'm not sure if I am good enough to get to the new creatures. Were the cobra looking things new? -- I had those on two rounds in a row.

 

When I died, the ship I escaped in was a jumbled sprite.

[Nukey Shay]

Thanks for the headsup. The page number wasn't being stored.

 

Anyway, the original game featured 7 alien types. Each type is repeated, and then the game loops back to the first type (a total of 14 waves). In order, they are a fat snake-like creature, a tall walker, a dog, the cobra snake, a bat/bird, a phantom-type shape, and Pacman.

 

I increased the table to include 9 more alien types (for a total of 16), but I only had GFX space to fit 7 add'l in. The remaining 2 types are repeats of previous creatures...making a total of 32 waves. Following the original 7, they are a "Sneaker", Donkey Kong, the Pterry from Joust, the Blob, a Yar, an Alien facehugger, the cobra snake (repeat), a Phoenix, and the fatter snake (repeat). The way that the game is coded, it allows for 128 creature types if Romspace were available (!). It's not required that they all share the same page in memory...but allowing the pointer to drift that high might have undesirable side-effects (like being impossible to play). Additional coding can prevent this.

 

 

I fixed the game here, and added a "trainer" mode as well. In that, you no longer have to destroy any meteors, you have infinite fuel, and the ground laser will not fire. The downside is that you don't score any points either, but you can at least get a look at all the creatures Use the B&W switch to flip on trainer mode. Sorry, it doesn't provide 7800 console detection.

 

NOTE: Due to additional bitmap sharing, the "1" character looks different than the original, and the game selection # will appear on the far right of the window.

 

PAL binary added (color of shuttle is still incorrect, tho).

Cosmic_Ark.zip

[uosipa llamxew]

Heh, maybe it's a problem with emulation, but that last binary ran kind of crazy for me. I couldn't shoot. After a death, the ship went to a planet (you could see the wandering aliens), but I couldn't take out my abducting ship... and another asteroid came out of nowhere and blew up the mother ship.

 

/edit

 

I just tried again and it turns out this happens in attract mode. I forgot that the game reset key is different in Stella than in z26.

 

I played in the trainer mode to see all of the creatures. Would it be very difficult to have them change after each asteroid round? Also, it seems that at a certain point, the creature in the abduction round always returns - the first creature.

 

Cosmic Ark is one of my favorites from way back... I'm enjoying the improvements you have made.

Edited April 4, 2008 by mojofltr

[Nukey Shay]

The first and fourth creatures return because I didn't have enough space to add all 16...the entire set of creatures loops every 16 changes (32 planets). You can have this loop sooner (so that each planet has the next creature) by removing 1 byte...

 

L1C05:
   lda	#$40				   ;2
   sta	$DA					;3
   sta	$A8					;3
   lda	#$C0				   ;2
   sta	$A9					;3
   lda	$A1					;3 load planet #
   lsr						   ;2 (2 planets each creature)
   sta	$F1					;3

 

That LSR near the bottom is making the change happen every 2 planets. Simply stick a semi-colon in front of it (or erase the line).

[DarthDuke]

On 4/3/2008 at 4:23 AM, Nukey Shay said:

Thanks for the headsup. The page number wasn't being stored.

 

Anyway, the original game featured 7 alien types. Each type is repeated, and then the game loops back to the first type (a total of 14 waves). In order, they are a fat snake-like creature, a tall walker, a dog, the cobra snake, a bat/bird, a phantom-type shape, and Pacman.

 

I increased the table to include 9 more alien types (for a total of 16), but I only had GFX space to fit 7 add'l in. The remaining 2 types are repeats of previous creatures...making a total of 32 waves. Following the original 7, they are a "Sneaker", Donkey Kong, the Pterry from Joust, the Blob, a Yar, an Alien facehugger, the cobra snake (repeat), a Phoenix, and the fatter snake (repeat). The way that the game is coded, it allows for 128 creature types if Romspace were available (!). It's not required that they all share the same page in memory...but allowing the pointer to drift that high might have undesirable side-effects (like being impossible to play). Additional coding can prevent this.

 

 

I fixed the game here, and added a "trainer" mode as well. In that, you no longer have to destroy any meteors, you have infinite fuel, and the ground laser will not fire. The downside is that you don't score any points either, but you can at least get a look at all the creatures Use the B&W switch to flip on trainer mode. Sorry, it doesn't provide 7800 console detection.

 

NOTE: Due to additional bitmap sharing, the "1" character looks different than the original, and the game selection # will appear on the far right of the window.

 

PAL binary added (color of shuttle is still incorrect, tho).

Cosmic_Ark.zip 20.93 kB · 152 downloads

I really enjoy Cosmic Ark! Will be cool to try it with additional creatures to rescue.  

[alfredtdk]

Cosmic Ark is a game that deserved an update. My congratulations on the addition of new creatures.