No mcn. I think it's not about Card readers. This feature is not added by the card issuers in SL. Recently i saw one of foreigner presented his card in KFC and he had to enter the PIN number to complete the transaction but i inserted my chip card into the SAME POS machine but i wasn't able to enter anything. I put the typical signature on the slip. that's mean POS machine is able to handle that kind of CHIP cards but my local Credit card is not supported for it.
Now this feature is supported in many card readers in SL mcn. Are you sure the limit is $100 in overseas countries? In UK that is £30. I know it very well. but i have no idea about USA. In SL, it's 5000LKR.
Yes..I was in Egypt, Greece a two weeks ago - only when it's over $100 it requested for the PIN. Quite possibly it's a value set by the card issuing bank.