as far as i know this shader from ati is exactly the same as in the shaderx book. i just did some changes to it so that it works with a6 and i created some grass models for it.

for learning the basics about shaders i read the vertex- and pixelshader introductions by wolfgang engel -> www.direct3d.net. they are great! the assembler language is easy but for more complex shaders my maths skills are somewhat lacking! for example vertex shaders have to use taylor series to calculate sine values and i don't really understand how taylor series work!