The author discusses how to detect PS2 emulators through exploiting a multiplication issue in the VU developer manuals, where 1 * X may not be the same as X * 1. The process involves identifying a number that triggers this problem, such as 129.5, and checking the results through a straightforward method using specific registers. Currently, known emulators like PCSX2 do not reproduce this behavior. The author rates the difficulty of this detection as 1/5 and hints at choosing a more challenging task next time. This summary highlights the unique approach to testing PS2 emulators and the technical details involved.
https://fobes.dev/ps2/detecting-emu-vu-floats