Transistor Powered, Because That Totally Means Something
In Tales of Suspense #48, artist Steve Ditko decides that Iron Man should look a bit more modern and that though leads to the creation of this new look.
For a much longer version of the above, with lots of tech goodies, check this out. This sequence starts the tradition of treating the science fiction elements of Iron Man as science fact, complete with schematics.
This armor was tweaked from time to time and had some out there features, like the time Tony Stark thought Iron Man needed a nose.
And impractical features like roller skates.

First appearing as an attempt to kill U.S. soldiers.
The best part about this armor though was that it was constantly referred to as “transistor powered.” For those who don’t understand why that’s odd, transistors don’t power anything. It was merely the application of a buzzword.
Greg Land was drawing Iron Man? Where on earth was he finding porn of guys in armor?