Dodo is an engine to create and distribute text adventure games (aka “interactive fiction”) for the C64. It is written in the Commodore’s own BASIC V2.0 with all its limitations, especially with regards to memory and execution speed. This means that Dodo is quite rudimentary, for example there is no support to save and load game sessions, nor for animated NPCs. I feel the limitations of the C64 and working around them give the idea its own charme and challenge.

The concept is simple. The engine provides a framework in the shape of a BASIC program. To turn this into a working game scenario, the game developer extends this BASIC program with two sections of his own:

  • A DATA section which contains the game configuration, ie objects, rooms, names, properties etc.,
  • A code section with subroutines which determines the non-standard reponse of the program to particular user actions — for example when “open bottle” will not just open the container, but release the djinn inside in addition.

So, while other IF authoring systems like Inform or TADS are interpreters for scenarios written in their particular language, in Dodo the scenario code is written in the same language as the framework and loaded “piggy-back” on top of it.

Dodo is free and (naturally) open source.


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I am Elmar Vogt, a tech writer from Germany. Please leave a comment on the blog pages, or use the contact form to get in touch with me!

 

“Dud, the Dodo” was designed and drawn by Bryan Hillesheim.