Don't all those components and cords look untidy? You've got to have your credit card terminal right there at the sales counter, but it can sprawl all over the place. I also found that the angle was awkward both for swiping the card and reading the screen.

I took some 1"x8" lumber that was in the garage and made this angled support for the terminal.

The bottom is open. Here's the side that faces the customer:

Notice that the power supply has disappeared from sight. It's inside the box. I also cut a slot so that the power cord for the adding machine could run underneath, making that a little more tidy. The last step is to fasten the PIN pad near the top of the sloping face with some right-angle hooks from the hardware store. A coat of varnish finished the project.