What kind of keyboard is this?

[Win Heagy]

I picked this up at Radio Shack about 25-30 years ago and have been
hauling it around ever since.

http://imgur.com/oNEcRFv,VacFqrY#0
(There should be two images...a link to the second.)

It was a surplus thing that RS was selling on the parts wall and I
grabbed on the off chance I'd need it someday.  I lost the cardboard
top to the plastic bag it came in, so I know nothing about it.

Anyone have any idea?

Thanks...Win