Your "eyes" and your "ears" are rigged to help you without cluttering up your attention, too. Say you have three audio circuits, common in a marauder suit. The frequency control to maintain tactical security is very complex, at least two frequencies for each circuit both of which are necessary for any signal at all and each of which wobbles under the control of a cesium clock timed to a micromicrosecond with the other end—but all this is no problem of yours. You want circuit A to your squad leader, you bite down once—for circuit B, bite down twice—and so on. The mike is taped to your throat, the plugs are in your ears and can't be jarred out; just talk. Besides that, outside mikes on each side of your helmet give you binaural hearing for your immediate surroundings just as if your head were bare—or you can suppress any noisy neighbors and not miss what your platoon leader is saying simply by turning your head.
Since your head is the one part of your body not involved in the pressure receptors controlling the suit's muscles, you use your head—your jaw muscles, your chin, your neck—to switch things for you and thereby leave your hands free to fight. A chin plate handles all visual displays the way the jaw switch handles the audios. All displays are thrown on a mirror in front of your forehead from where the work is actually going on above and back of your head. All this helmet gear makes you look like a hydrocephalic gorilla but, with luck, the enemy won't live long enough to be offended by your appearance, and it is a very convenient arrangement; you can flip through your several types of radar displays quicker than you can change channels to avoid a commercial—catch a range & bearing, locate your boss, check your flank men, whatever.
If you toss your head like a horse bothered by a fly, your infrared snoopers go up on your forehead—toss it again, they come down. If you let go of your rocket launcher, the suit snaps it back until you need it again. No point in discussing water nipples, air supply, gyros, etc.—the point to all the arrangements is the same: to leave you free to follow your trade, slaughter.
Of course these things do require practice and you do practice until picking the right circuit is as automatic as brushing your teeth, and so on. But simply wearing the suit, moving in it, requires almost no practice. You practice jumping because, while you do it with a completely natural motion, you jump higher, faster, farther, and stay up longer. The last alone calls for a new orientation; those seconds in the air can be used—seconds are jewels beyond price in combat. While off the ground in a jump, you can get a range & bearing, pick a target, talk & receive, fire a weapon, reload, decide to jump again without landing and override your automatics to cut in the jets again. You can do all of these things in one bounce, with practice.
But, in general, powered armor doesn't require practice; it simply does it for you, just the way you were doing it, only better. All but one thing -- you can't scratch where it itches. If I ever find a suit that will let me scratch between my shoulder blades, I'll marry it.
There are three main types of M. I. armor: marauder, command, and scout. Scout suits are very fast and very long-range, but lightly armed. Command suits are heavy on go juice and jump juice, are fast and can jump high; they have three times as much comm & radar gear as other suits, and a dead-reckoning tracker, inertial. Marauders are for those guys in ranks with the sleepy look—the executioners.
As I may have said, I fell in love with powered armor, even though my first crack at it gave me a strained shoulder. Any day thereafter that my section was allowed to practice in suits was a big day for me. The day I goofed I had simulated sergeant's chevrons as a simulated section leader and was armed with simulated A-bomb rockets to use in simulated darkness against a simulated enemy. That was the trouble everything was simulated—but you are required to behave as if it is all real.
We were retreating—"advancing toward the rear," I mean—and one of the instructors cut the power on one of my men by radio control, making him a helpless casualty. Per M. I. doctrine, I ordered the pickup, felt rather cocky that I had managed to get the order out before my number two cut out to do it anyhow, turned to do the next thing I had to do, which was to lay down a simulated atomic ruckus to discourage the simulated enemy overtaking us.
Our flank was swinging; I was supposed to fire it sort of diagonally but with the required spacing to protect my own men from blast while still putting it in close enough to trouble the bandits. On the bounce, of course. The movement over the terrain and the problem itself had been discussed ahead of time; we were still green—the only variations supposed to be left in were casualties.
