Does anyone have $700 to spare that I can have?

Great visualization.

Article about the design of the revolutionary (at its time) HP-35 calculator.

"A market research study, however, warned that the device would be too expensive and there was simply no market. That didn’t matter to Hewlett. He decided he wanted one and said “We’re going to go ahead anyway.”

... and it was wildly successful. This was the philosophy behind the iPod's design much later at Apple.

A wiki with many many connectors, cables and adapters pinouts.
If you can't think of a reason to check it out, then you are not a (true) engineer.