Are Master Systems territory protected?

[Vertigo]

Got a US Wonderboy The Dragon's Trap.
Got a UK Master System 2.
One won't work with the other.
I've read that Master Systems and their cartridges aren't territory locked.
I've also read the opposite, that the odd cartridge or two are protected.

Sort this out for me please?

[Endymion]

Well I do know that there is a language change in the hardware. When I modded my Genesis then used the Power Base Converter, Power Strike became Aleste. I don't remember offhand what other games may have done this. I didn't try messing with it on my Master System but I did see a similar jumper set on the board when I opened it up.

[Guest]

Well I've just bought a powerbase and also been told that there's no lockout again today so either way I'm going to make this fucking thing work