and ask it to decode the original Pronto Hex. It will tell you that this is a variant type of NEC (I've never heard of the term NEC -TC101), which the IR community has dubbed NEC-rnc, where rnc stands for Reverse Nibble Complement. It decodes as NEC-rnc device 1, function 52.
To generate other Pronto Hex, go to the Generate tab, select NEC-rnc, enter 1 in the D box, leave S blank, and enter e.g. 55 in the F box.