...right, I thought a "Back to the future" cache is missing from the Parnitha field !
So this cache is a shrinked version of the early computer games ! Back in 1972 Atari company introduced this console sized game under the name 'Pong'. Pong is now part of the permanent collection of the Smithsonian Institution in Washington, D.C., due to its cultural impact. And this cache gives you the opportunity to beat the computer opponent using state of current shringing technology in electronics.
You need an AA battery and if you are successfull and have five wins you will get the coordinates of the Logbook.