Thank you for the warm welcome and suggestions!
I'm an argetinian, so the program is written in spanish.
I'll keep a bit more on the Terrie's Ritchies Course, and i will come back over this program with these suggestions. The array sounds interesting. I also was thinking if it was posible to use DATA...READ, or maybe reading a .txt file. But i agree that the CASE SELECT...END CASE looks awfull, was just a very BASIC way to do it. I came in this programming stuff after playing TIS-100, were my rule "make it work first, then optimize".
I'll set the INKEY$ ways soon, i just wondered if can be done simply with INPUT, but you guys are right, untill ENTER is pressed the program is paused, no chance this way.
No title or too many fancy thisng for the moment, but it can be more user friendly. Im more focused at start on a fully operational, clean code program, then we lit the fireworks. XD
The idea would actually be to make a function/snippet that other people of the community can use inside they own programs.
The funny part is gonna be make it work the opposite way: ROMAN in > INTEGER out hehehe
Again thenk you, and sorry for my english. (feel free to correct me on this as well if you like)