Texture Mapping 32 bit float


I have a ATI Radeon 9700 and I want to use it to do matrix multiplication, this is possible but the problem that I am having is when I put a matrix in as a texture and then read the pbuffer the values are there but they are 8 bit long 0 - 255, do you know how to make it 32 bits long. Like I want to put in 15.2 and I want the pbuffer to read back 15.2, right now it reads back 255

Any help would be greatly appreciated


what about using a floating point pbuffer as rendering target ?
for more details download the ati openGL SDK and read the file “Radeon 9700 OpenGL Programming and Optimization Guide.doc”

check this out: http://www.ati.com/developer/sdk/radeonSDK/html/info/Prog3D.html