Coming Soon Jungle Hunt DISASM

[Captain Cozmos]

In an effort for more programing education I have decided to disassemble Atari Jungle Hunt.

I am working on it now, learning some parallax routines, scrolling ect...

I have no issues with releasing the final work with as much commenting as I can figure out.

 

So far I have identified pretty much the main aspects of the game.

It starts out assigning a stack, clearing ram but what I have discovered is that it uses ram as a 768 byte screen buffer before it sends everything to vram (at least this is how I am interpreting it)

No OS7 BIOS routines as expected for an Atari Game.

Some very optimized graphic writing routines that sets the control ports directly then sends it all out through the data port with otir

 

I found it's equivalent of an NMI and sound routines.

 

You would also be surprised at how it uses sprites where patterns would be over engineered programing.

It does not use register 4 for scrolling but changes the patterns directly into vram

 

It was a very well thought out system and every time I disassemble these thing I get some great insight.

 

I've used some of these techniques in my Haunted House project

Being as the only way to efficiently have a large play field without the ram, it has to stay in rom and be updated within a 640 byte screen buffer.

That was the only way I can overlay the candle effect before sending it to vram.  I've been able to do this in real time within the 1k Colecovision ram limitation.

 

As far as the Shamus rewrite, I am working on updating my pattern system for 16x16 patterns that will also interpret what's adjacent in all 8 directions.
This will also come in handy if I ever decide to write a Zelda style RPG.

 

Edited August 26 by Captain Cozmos

[Tornadoboy]

Someone should hack it into being Pirate Pete, which was pretty much just a Jungle Hunt hack to start with 

[Captain Cozmos]

16 minutes ago, Tornadoboy said:

Someone should hack it into being Pirate Pete, which was pretty much just a Jungle Hunt hack to start with 

Once I release the code you can hack it to look like the original Tarzan.  I think it was called Jungle King.  Change because of Copyright.  I don't remember.  My mind is older than dust at this point.

 

However, if anyone changes anything then have fun doing it.  I just ask that some enterprising knuckle head doesn't throw it on a cartridge and sell it.  Especially when I did all the work.
 

If I get wind of it I won't disassemble and release anything new.  All of this is for fun and programing knowledge.

Another project on my radar is to return Taper back to the arcade version.  Again, for fun and knowledge.

Edited August 29 by Captain Cozmos

[Tornadoboy]

Amen on nobody selling carts based on it, they would just be ripping off your work.

 

If I recall they had to change it from Jungle King to Jungle Hunt because the copyright holders of Tarzan said they were ripping it off, which they pretty much were, especially with the Tarzan scream at the beginning. I have no idea what the story behind Pirate Pete is other than it's a rather elaborate mod. 

[Captain Cozmos]

1 hour ago, Tornadoboy said:

Amen on nobody selling carts based on it, they would just be ripping off your work.

 

If I recall they had to change it from Jungle King to Jungle Hunt because the copyright holders of Tarzan said they were ripping it off, which they pretty much were, especially with the Tarzan scream at the beginning. I have no idea what the story behind Pirate Pete is other than it's a rather elaborate mod. 

I could always add an option to change to whatever character you want.  You could have all 3 or even Pitfall Harry.