TI-83

The TI-83 was a graphical calculator from Texas Instruments. It had a black and white display, some buttons and a Z80 processor, and it allowed you to write programs in assembly language.

This I did, and I also managed to extract the ROM code from within the calculator (not a trivial task, since the memory was paged), and investigate it. I discovered some things which were of great help to me and to others in the TI-83 community. Today, this sort of activity could very well be illegal in the USA, and perhaps soon in Europe.

The TI-83 community thrived in the 1990:s, but unfortunately, Texas Instruments have upgraded their ROM software in a way which is not backwards-compatible, so if you buy a TI-83 now, you won't be able to run all the old programs.

My programs:

• WizMusic - My first music program for the TI-83. Plays the Bossa Nova-theme from C64 Wizball, originally composed by Martin Galway. You need a 2.5 -> 3.5 mm adapter to be able to connect a pair of normal stereo earphones to the link port of the calculator.
• Complications - Another piece of music for the '83. This one was originally composed by Tomas Danko.
• The very first full-blown demo for the TI-83 - RiDE is here to kick some ass.
• The graphical adventure game Stranded, my first game for the TI-83. You can also play this game online.

Research

I spent a lot of time disassembling and investigating the TI-83 ROM, to see if I could find anything useful. The following discoveries have been used extensively by the TI-83 community:

• Getting string input
• Getting numeric input

Source code

Stranded

The source code for Stranded is now freely available, together with a brief guide to the layout of the game and its data structures. Download the complete source code. (240k) Inside the archive you will find a file called the_guide.text, which tries to explain how the game works. Note that you can play Stranded online.

RiDE

A lot of people have asked me to release the source code to RiDE (and I'm flattered, of course). Well, here it is! Warning: This is a demo. The code does not try to be clean or understandable. You won't be able to compile it without the data files either. However, tunnel.c was used to precalculate the tunnel data.