It seems that aviation has gone full circle. It started with the 100 seat “RJ’s” like the DC-9-10 and 737-100/200 as John stated. Now we have manufacturer’s breaking new ground (?) with the EMB-170/190, CRJ-900 and the recent announcement by Bombardier of a 100 seat aircraft.

As for the differences, I don’t think it matters how many seats they have. Basically John, your asking what’s different between the original jet entries and those that we see now. The technology of those DC-9-10’s were the same as the DC-8’s of the era. The same tech found in the EMB-170/190 can be found in the new Boeings and Airbus’s.

– Fly-by wire
– Glass cockpits
– FMS/GPS navigation
– Numerous automatic/manual safety features (ie automatic thrust increase during an engine failure)
– Less polutants and all around quiter inside and out.

Those are just a few that I could think of off the top of my head.