When I was a kid, I remember SquareOne TV very fondly. I even got the weekly activity books (which nobody seems to remember or mention besides myself) and remember being so excited when they came. It really turned me on to math and eventually computers.

Here’s one of the better resource collections for SquareOne. But if you want to check out some episodes, you can see some of them on YouTube:

• Square One TV Playlists 
• Mathnet Playlists