Hence the "originally" part prefixing my post. I absolutely agree it later become a monetary thing (bare in mind DVDs came a long time after the time period I w

Hence the "originally" part prefixing my post. I absolutely agree it later become a monetary thing (bare in mind DVDs came a long time after the time period I was discussing) but many early consoles didn't have region locking and some that did, did so because games timed for NTSC consoles would have ran slower on PAL systems due to the difference in refresh rates between PAL and NTSC (50Hz and 60Hz respectively). You can see this in effect whenever you play games on a modded Mega Drive (for example). That all said, some NTSC games were still released for European markets without changing their timings. Sonic is one example of this - it runs slower, the music plays slower etc. For that reason I usually play Sonic on NTSC console rather than the PAL one (yeah, I have a whole room full of old computers and games consoles. It's sad but I love it).