HP 50g User Manual page 806

Right-shift ... functions of the calculator's keyboard
Right-shift functions
The sketch above shows the functions, characters, or menus associated with the
different calculator keys when the right-shift key ... is activated.
The functions BEGIN, END, COPY, CUT and PASTE are used for editing
purposes.
The UNDO key is used to undo the last calculator operation.
The CHARS function activates the special characters menu.
The EQW function is used to start the Equation Writer.
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