Wait, PCSX2, a popular PS2 emulator, uses ISO files. Maybe the user is using an emulator that now supports CHD, or there's a new tool. Alternatively, maybe they're using a frontend that organizes CHD files, but that's more relevant for arcade emulators.
First, I need to understand what a user is asking. "PS2 CHD ROMs upd" – probably an update related to PlayStation 2 CHD ROMs. CHD stands for Compressible Hash Data, which is a format used in emulators to store game data efficiently without decompressing the entire file. The user might be looking for an update on how to handle PS2 CHD ROMs, or maybe there's a new version or tool available.
Wait, PS2 emulators usually emulate the hardware, so maybe CHD isn't as common as in arcade emulators (where MAME uses CHD for cabinet data). For PS2, ISO files are more typical. So maybe the user is referring to a different use case, like using PS2 BIOS files in a different format? Unlikely. More likely, they have PS2 game backups stored as CHD files and need help updating them or converting them.