Nascar Rumble -usa-.chd |best|

The file extension is the first clue. stands for Compressed Hunks of Data . It is not a standard ROM file (like .zip or .bin ). It is a format developed by the MAME (Multiple Arcade Machine Emulator) project.

prefer this format because it saves storage while keeping everything perfectly preserved. Why We Still Love NASCAR Rumble NASCAR Rumble -USA-.chd