<p>Vintage Electronic "Master Mind" LED Handheld Game by Invicta Games, Made in Hong Kong, Copyright 1977<br></p>
A good source of information on vintage handheld electronic games is the Electronic Handheld Game Museum (<a rel="nofollow" class="external text" href="http://handheldmuseum.com/">Handheldmuseum.com</a>).
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/51764518@N02">Joe Haupt</a> from USA
CC BY-SA 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/51764518@N02/8683833265/">Vintage Electronic "Master Mind" LED Handheld Game by Invicta Games, Made in Hong Kong, Copyright 1977</a>