IBM 5155 - The Numeric Keypad

The Numeric Keypad
[[§]
Pressing the Numeric Lock key once places keys 0
through 9 in the numeric mode. Pressing the Numeric
/"'""".
Lock key again returns keys 0 through 9 to cursor
control.
[1'(;01J
The Scroll Lock key is defined in your operating system
or application program manual.
3-18 Keyboard