NetBSD 10.x Kernel Math_emulation

This is my battle-worn, falling-apart laptop rocking an #i486SX CPU from the early ’90s. It’s so ancient that it doesn’t even have an FPU (Actually, that’s not true, they just cut-out FPU from i486DX to make CPU cheaper)! Anyway, I’ve always dreamed of running a modern UNIX-like OS on it. So, I spent some time resurrecting math emulation in the #NetBSD-10.x kernel, and guess what? I did it! But here’s the kicker—the very moment I finished compiling the kernel, ready to test my work, my laptop decided to stop recognizing the Enter key. Just like that. Now, I have no idea if my FPU emulation actually works or not! So, #retrocomputing folks—if anyone out there has an i486SX machine and is willing to give this a spin, I’d really appreciate it! UPD: 11.03.2025: Significant progress FPU-emulation code is triggered by the kernel – done First successful addition operation using FPU instruction: fadd 3.5 + 2.5 for single precision short real – done All other instructions and formats to ... Read full article.