Robert Meloche not sure where you got a "replacement adapter cord" from but if it does not fit it is most likely because it is not meant for your model. Unless we know what adapter you have we cannot even comment on any pinout etc, The Dell Inspiron 1100 uses a PA-9 power supply so something [http://www.ebay.com/itm/For-Dell-PA-9-Inspiron-1100-2600-5100-8200-AC-Power-Adapter-/271615391552?_trksid=p2385738.m2548.l4275|like this] or [https://www.amazon.com/Dell-Inspiron-Charger-Adapter-Battery/dp/B005NWVU54|this one] should work.