Velocity on a flat plane is a two number vector. It has a speed value and a direction. Once upon a time, IBM/Microsoft claimed a faster computer because they used single precision math as opposed to the extended single precision used in the Apple II. Single precision (32 bits) is useful in some engineering applications and certainly for games. Double precision (64 bits) is generally accurate enough for most purposes including calculating mortgage payments; however, spreadsheets long ago switched to extended double precision (80 bits) for their calculations. ANSI/IEEE-STD-754 is the defined standard for computer math. Texas Instruments has made a living selling a separate vector processor chip for years. I am not familiar with built-in vector instructions for IBM, Motorola, Intel, or processors nor am I aware of any simple support in C. I would think that one would need a higher level language to get vector instructions. C IS assembly language and to optimize its use on any specific processor requires specialized programming and/or libraries. So what! This is true for all functions on all processors. Most code is not optimized and it still works. By the way, he is saying that Apple/Motorola advertising executives are bragging about a minor glitzy thing. What a revelation. sam