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Stellar Fortress v0.23

Posted by TROGDOR, 24 May 2008 · 345 views

Stellar Fortress
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Entitlement.

Attached File  sf23.zip (20.64K)
downloads: 229
New Features:
sf22.asm 3/2/08
- Added preliminary title music.
- Reorganized bank data.  All kernels will now live in bank 2.  Bank 1 contains the VBlank and Overscan.

sf23.asm 5/24/08
- Changed cannon graphics.  Uses lower vertical resolution.  Cannon is larger.  Now has 16 rotational animation positions instead of 8.
- Added Title Screen mode.  Press the fire button to begin the game.
- Added Title graphics.

To Do:
- Rewrite the kernel to squeeze out more cycles and allow for some extra features.
- Improve the Plasma Cannon graphics.  Currently only 8 directions are implemented.  This will be expanded to 16, as was done with the player's ship.
- Design the Stellar Fortress destruction animation.
- Title screen and title music.
- Targeting computer for missiles.
- Add starting level selection and gradual difficulty increase per level.

Known Issues:
- There seems to be a glitch in the title music.  It misses a beat every few seconds.  Gonna have to figure that out.
- The mapping for player shot collisions with the fortress shield are still off by a couple pixels.
- The final game will not have the fortress cannon shooting all the time (at least, not on most of the lower levels...)  I need to implement a feature that will detect when a hole has been poked in the shield so the cannon can fire out.

Development Notes:
I broke a lot of game features when I moved the banks around and added the title mode.  Most of the work I did for the last 3 months was cleaning up everything that was broken.  But the original functionality is back, and the reorganization will make future development cleaner.

I also beefed up my copyright notice, so none of my games will get Hozed.  For clarification, the games that I post in this blog are not open source, nor are they public domain.  I will retain all copyrights.  People are welcome to look through the code for ideas, and can reuse individual subroutines if they find them useful.  But I don't want any of these games placed on a ROM cartridge or CD without my permission first.





supercat
May 24 2008 9:18 PM
I'm not sure how CC2 and Stella implement FE banking, but you could make your game compatible with Z26's version of FE banking by having one bank RORG'ed at $D000 and the other at $F000 and omitting all banking instructions.  I would not be surprised if the same approach would work on Stella and the CC2 (the simplest way to support FE banking is simply to use bit A13 to select banks.  It's not wired on a real 2600, but emulators and 7800 cartridges have access to it.

If such binaries would work on Stella and the CC2, you could release binaries that people could play on those platforms, but that would be somewhat tricky to convert to use on a real 2600 cartridge.  Use conditional assembly so that each build gives you both an "FE" and "F8" version; the F8 version would be used for testing by yourself or trusted people; the FE version would be for general release.
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batari
May 24 2008 11:36 PM
I personally converted the public release of Gingerbread Man to UA bankswitching, which the Kroko and CC/CC2 all support.  I considered FE but decided against it, as Kroko cart users wouldn't be able to play it.

If you want to go further, it's possible to write code that will run only on an emulator and fail on real hardware.  There are several ways to do this, but I won't post them here.
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TROGDOR
May 25 2008 2:01 AM
Those are good suggestions, but I'm going to take a different approach.  I found this copyright lawsuit story to be inspirational.  The photographer in this story represented himself, although given the detail in the case, he must have had some legal background.  Still, the result of the case is interesting.  He was only awarded $4400 for the product that was infringed.  But, he was awarded an additional $10,000 statutory damages for willful infringement, and another $5000 for the removal of the photographer's watermark.

So my solution is simple.  I've added a watermark to my ROMs.  (Good luck finding it.)  If the watermark is not removed, it will be easy to prove that my work was stolen.  If the watermark is removed, I can collect another $5000 in damages.  So certain unnamed people (cough Randy cough) had best be careful or they'll be looking at a $25 + $10,000 + $5,000 lawsuit if my copyrights are not respected.  It would only take one lawsuit like this to shut him down permanently.

I encourage other developers to follow in suit.  (Pun intended.)  I also think it's a good idea for anyone releasing a homebrew game to clarify the copyright status of the game in their blog/post and with a README.txt included in the distribution.  Unless they really don't care, which is also fine.
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batari
May 25 2008 4:41 AM
Whatever works for you.  BTW, it's not Randy who's actually selling those games, but he is making the carts.  Randy apparently has made no effort to determine if he is violating anyone's intellectual property when he makes a cart.  Therefore he has claimed ignorance as a defense for when he has made a pirate cart.

I have heard a rumor that Randy is trying to redeem himself, however.  We'll see.
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Eckhard Stolberg
May 25 2008 7:06 AM

batari, on Sun May 25, 2008 7:36 AM, said:

I personally converted the public release of Gingerbread Man to UA bankswitching, which the Kroko and CC/CC2 all support.  I considered FE but decided against it, as Kroko cart users wouldn't be able to play it.
The 2600 Cuttle Cart doesn't support UA bankswitching. If you don't want to lock out people from trying your games, you'll need to find a different way of protecting them.
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batari
May 25 2008 1:40 PM

Eckhard Stolberg, on Sun May 25, 2008 8:06 AM, said:

batari, on Sun May 25, 2008 7:36 AM, said:

I personally converted the public release of Gingerbread Man to UA bankswitching, which the Kroko and CC/CC2 all support.  I considered FE but decided against it, as Kroko cart users wouldn't be able to play it.
The 2600 Cuttle Cart doesn't support UA bankswitching. If you don't want to lock out people from trying your games, you'll need to find a different way of protecting them.
Thanks - I didn't realize that. I will work up a 3F version or something.
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