There were two kinds.
The first was made in the 60s, and looks like the familiar 10/22:
These are pretty sought-after guns. I bought the first one I saw at a reasonable price, and I ain't selling it anytime soon. It is light and handy, and good things happen when that big bullet lands on target. It only holds 4 rounds in the tube magazine, and that may have limited its popularity. They sure get lots of love nowadays, though.
The other used a detachable rotary magazine, and looked more like a Mini-14.
I prefer the older tube fed version, but the latter style has fans, too.