Simply stated: you won't be able to use the HP-28S without reading the manual, at least partially.
Here's a link to the quick reference which is the most condensed documentation you will find:[url]http://www.scribd.com/tmartin_79/d/5974 ... -Reference
You do need to know how to use soft-menus to make use of it.
Regarding your specific questions:
- you will need the shift key to clear your stack; or type and enter CLEAR
- the DROP key will delete the last item on the stack
- yes, there're ROLL and ROLLD and a good bunch of other stack manipulation functions in the Stack soft-menu
Hope this helps.
For help with the HP-28S calc visit http://groups.google.com/group/comp.sys.hp48/topics
The forum here is for question related to ND1, an iOS app, following in the footsteps of the HP-28S and HP-50g calculators.