You must have flown a type of aircraft different from the RJ
-100 or the MD
Even though the MD83s arrived around 1993, they were for Avianca
which was a totally separate company by then.
Thinking it was a RJ
-100 is absolutely ridiculous; in 1990 SAM probably didn't even have the idea what an Avro was, the RJ
-100 didn't arrive until 1995 or so.