I found that students were still confused about input and output, and even between hardware and software. So I decided in my next class to add a prop - a computer (cpu tower) with nothing attached. It's a computer, but how can we get it to do anything or even store anything? This led to a more natural discussion of inputs and outputs. Then I asked, ok we got it to do something, or store our files, but how do we know it actually worked? Which led to a discussion of outputs. I felt this really helped students understand the concept on inputs and outputs.