This is our Texas Instruments "Advanced Scientific" TI-81. It is a portable
machine capable of storing several useful programs. I am most proud of a
spoke length calulating program which I adapted from Jobst Brandt's excellent
book "The Bicycle Wheel".
:Disp "(ALL UNITS MM)"
:Disp "CROSS PATTERN"
:Input X
:Disp "NUMBER OF SPOKES"
:Input N
:720*X/N->T
:Disp "HUB DIAMETER?" /* This is the diameter of the circle
:Input H made by the holes */
:(H/2)*sin T ->A
:Disp "RIM DIAMETER" /* This is the _inner_ diameter of your rim */
:Input D
:(D/2) - ((H-2)*cos T) -> B
:Disp "FLANGE SPACING, FROM CENTER" /* Center of the hub shell, that is. */
:Input C
:[sqrt] (A^2+B^2+C^2) - .95 -> L
:Disp L
:Disp "+1/-1 MM FOR REAR DISH" /* Add 1 mm to the left, subtract 1 mm from
:END the right to account for dish on 7/8 speed */