Titanium logo.png 929bytes
Titanium is my first game for the Ti-99/4A written purely in assembly language. The name is a reference to the C64 game Uridium - a favorite of mine - from which I have borrowed many ideas, and, of course, to the TI. The game engine and the graphics on level 1 are based on my half-bitmap mode, vertical scrolling demo. (I would like to do a proper port of Uridium for the TI at some point, but that should be based on a different technique for the scrolling.)
The game requires a disk drive, a 32K memory expansion, and a E/A cart or similar to run it. To start the game, insert the disk in any drive and use E/A option 5 to run DSKX.TITANIUM. I have not tried it with a real floppy drive, but I expect it to work.
The gameplay is very simple: shoot all the targets, e.g. pyramids, to reach the next level. Avoid the blinking spheres and the enemy ships. Use joystick 1 or S, D, E, X + space to control the ship. P pauses the game. I don't know if it's too easy or too hard - it's difficult to tell when you have tried it so many times.
This is the first game I'm aware that’s using the F18A, but only to avoid the sprite duplication issue that exists in the old VDPs (9918A, 9928A) in half-bitmap mode. If an F18A is detected the program uses a standard half-bitmap mode with only one pattern table. If an F18A is not present it uses three pattern tables, but still only one color table. This eliminates the problem on the old hardware, but also lowers the frame rate because it doubles the amount of data that must be sent to the VDP. If you press F on the start page you can manually switch between F18A mode and standard mode. This allows you to see the sprite duplication problem in action on the old hardware, and can also be used to increase performance on MESS where the F18A is not detected (the F18A is detected in Classic99).
I'm using Tursi's mod player for the music on the start page. I tried to compose my own music, but it ended up sounding very similar to the Blade Runner, so I decided to use that as my main theme. Within the game I'm using my own, simpler sound player and excerpts from Bach's 'toccata and fugue in d minor' - a reference to Gyruss, which is another favorite of mine.
I consider the game in its present stage a beta version. I welcome suggestions for improving the gameplay, but major additions at this point are likely to slow down the game. For now I will fix any reported bugs and release the first version, and in a month or two when I regain some energy I may release a version 2. More levels/maps could easily be added without affecting performance.
I include the full source code and data files. The maps were created using Magellan, the music using mod2psg2.
Thank you to everyone who has helped me on this project. It has been very interesting and a great learning experience, and I think it demonstrates that there's still some potential left in the old TI.
[Edit 14 Aug 2013] Added version 1.0 attachment. Titanium_1.0.zip 109.1KB 108 downloads. An XB loader is now included, and the E/A 5 file is called TITA.
64K bank switched (379) ROM image: Titanium3.zip 14.25KB 76 downloads