Why reverse a program when you can reverse a computer & CPU with custom ISA?
TL;DR: Custom homemade CPU
This CPU is a save file of Powder Toy;
From the website: "The Powder Toy is a free physics sandbox game... The game provides you with various building materials, liquids, gases and electronic components"
I have, in a moment of madness ;), decided to build a cpu, painting it by hand pixel after pixel...
Making a cpu is something that was on my "todo list" from some time and this was the perfect opportunity!
Here you can find a document describing the parts, how do they work, the program that it execute, and the flag.
Thanks anyone for playing!
Greetings from Italy
Nesos