user control:
        'n'       asks for n=2 to 7 (also asked at start of program) and resets the ncube
        'N'       animated increase of cube n, locks out forces 'C''V''B''D''F''H''G''g' or 'T' during

        'w'       toggles wiping the previous ncube render or not
        'c'       clears the screen

        'S'       adds 1 to the delay number starting at 20 mod to 0 at 28
        '!'       sets delay number to 0
        'f'       toggles a faster arrangement of the rotation math
        'v'       vert. sync.

        's'       cycles through a few spin modes (sets of angular velocities)
        'M'       cycles through alternate sets of spins for 's'

        'p'       cycles through palette subsets 
        'A''Q''W' plus, minus, and reset on parameter for custom VGA palette set, 'P'
        'P'       sets custom VGA palette; use 'p' to choose subsets
        '''       two alternate sets of range centers for 'p'
        'r'       toggle, old pixels fade away
        'z'       toggle, uniform oscillating color draw instead of dimmed by distance in and out of screen

        'd'       distorts ncube vertex coordinates by up to +/-.1 (starting scale is +/-root(n), or +/-1 unrotated)
        'b'       breaking distortion, like 'd' except edges separate
        'a'       shrink the ncube by 8% per coordinate
        't'       grow the ncube by 8.7% per coordinate
        'e''E'    expand cube from cube center: by 8.7%, by closeness to center
        'y''Y'    asterisk the cube, draft from 'e' or 'E'
        'R''X'    nudge cube left on screen; 'X', only nudge points near center, if any

        'C''V''B' selects/toggles contraction forces
        'D''F''H' selects/toggles draft contraction forces, drafts from writing 'C''C''B'
        'G'       contraction force on vertices somewhat or more above average distance from cube centroid
        'g'       skewed draft of 'G': 1st skew, 2nd skew, off
        'T'       spring force on edges other than length 2, edges stay joined at vertices

        '?'       key reserved for Commands Help and Status screen
        'esc'     hit escape to exit program
        'any other key' pauses/unpauses ncube animation

        ncube tenth-anniversary edition
        // calculates the pythagorean root for components transverse to screen 
        // and shades pixels in the edge line in a gradient,
        // the sense of it depending on the sum of the omitted coordinates

        ncube - rotating hyper-square program - 10th anniversary edition
        shades pixels vis-a-vis distance transverse to 2d screen in an 
        infinite rectangular prism 

        // calculates the pythagorean radical for the truncated component, 
        // the removed part, and colors in the edge line in a gradient,
        // the sense of it depending on the sum of the coordinates