What’s trivial in C++:

unsigned char f(unsigned char x) { return x ^ 0x51; }

is an absolute nightmare in Malbolge.

When new models are released, I’ve been running them through their paces on the Malbolge Board. (And I also ask them to improve the board itself, along with all of its backend code).

Until yesterday, a working .mal routine that (1) reads one input byte, (2) XORs it with 0x51, (3) outputs the resulting byte, and (4) halts using less than 2048 source bytes, eluded all efforts by frontier models. And I’ve been trying to make sure that I don’t leave any tokens on the table with my OpenAI and Anthropic subscriptions.

GPT-6 Astra came out yesterday and immediately cracked XOR-2048. As part of the debrief, I asked the model to generate a one-off web-app that illuminates the operation of its groundbreaking source. One instruction at a time. It’s fascinating to walk slowly through it, struggling to understand — at the dim outer realm of perception — this apparently extraordinary new critique of pure reason.