first pass

add simple clock first version
Revert "first pass"

This reverts commit 9e1301f6e3b7792cb060cbd0f9e3d0808aeab641.
Revert "Revert "first pass""

This reverts commit 830e7f0c81a7a17dc248642f1ae8ebe3f17fdb68.
code motion,
doc fixes, indentation