Can you recommend a decent online or software calculator? I'm looking for an online or software calculator that can show me the history of items I typed in, much like an expensive Ti calculator. 
Can you recommend any?

If you want a quick RPN calculator with print capabilities for standard calculations, I use Free42 which is compatible with HP42S (RPN). There is a print key to print when you need and you can configure the file used to save those prints. You can use skins to make it look the way you want, including the original HP calculator.
Free42 : An HP-42S Calculator Simulator
