Brainfck
After introducing BASIC and Forth as interpreted languages on the Steckschwein, it’s time to add another unique and productive language—Brainf*ck.
For those unfamiliar, Brainf*ck (or Brainf**k) is an “esoteric” programming language created in 1993 by Urban Müller, the founder of Aminet. You can read more about it on Wikipedia.
A compact Brainfck interpreter can be found here, originally developed for the Apple ][. This version served as the foundation for the Steckschwein adaptation. The Apple ][ ROM calls were replaced with custom code, and the interpreter loop was optimized using 65C02-specific instructions, making it smaller and faster. Although performance gains in Brainf*ck aren’t critical, the improvements are noteworthy.