Russ,

This helps me a lot. Just a few things I'm ashamed to admit that I don't understand what some of these lines do. As we didn't cover them in C class...

1. "#define A_0 (A_I0 | A_I1)" - everytime i type in A_0 it gets or'd with A_I0 and A_I1?

2. "static code char sequence[] = {
A_MINUS | A_0 | B_PLUS | B_67,
A_PLUS | A_33 | B_PLUS | B_67,
A_PLUS | A_67 | B_PLUS | B_67,
A_PLUS | A_67 | B_PLUS | B_33,
A_PLUS | A_67 | B_PLUS | B_0,
A_PLUS | A_67 | B_MINUS | B_33,
A_PLUS | A_67 | B_MINUS | B_67,
A_PLUS | A_33 | B_MINUS | B_67,
A_PLUS | A_0 | B_MINUS | B_67,
A_MINUS | A_33 | B_MINUS | B_67,
A_MINUS | A_67 | B_MINUS | B_67,
A_MINUS | A_67 | B_MINUS | B_33,
A_MINUS | A_67 | B_MINUS | B_0,
A_MINUS | A_67 | B_PLUS | B_33,
A_MINUS | A_67 | B_PLUS | B_67,
A_MINUS | A_33 | B_PLUS | B_67
};"
What is a static code char sequence[]? My guess is that it's an array with 16 values. What does the word static do for the array?

3. "#define set_motor(X) P1 = (P1 & 0xC0) | X" - I'm a bit confused with this line - the tutorial i read about macro's gave me this form "#define MULT(x, y) x * y" where whatever i typed in for x and y would be multiplied.

If you could please just teach me those few C concepts I think I can wrap my head around the rest.

Thanks very much for this,

Roque