Generally speaking, back in the day, many systems were interchangeable between NTSC and PAL, and vice versa.
The use of 'international' integrated circuits facilitated this; but finding how to switch from one standard to the other was not easy.
Finding out how to make the change was usually very difficult.
DVD players were a case in point. Region 1 and Region 2, etc.
Rather like todays TVs that can decode any international standard.
All down to International Marketing and which regions will pay a premium price to get the latest technology first (ie. before anyone else).