A couple thousand coders with specs provided by AMD haven't made OpenCL capable drivers for AMD GPUs. Doing it in the dark is never going to happen.
Just a peeve here - We had coders "tricking" GPUs into running semi-arbitrary code considerably faster than CPUs by writing it as custom shader routines, years
before OpenCL hit the scene (Google for "GLSL" or "Cg"). So yes, the possibility does
exist of mining on a completely non-CL-supporting platform.
That said, shaders (at least back then) had a fairly limited set of available operations they could do (mostly linear algebraic transforms on single or half precision floats, not bitwise ops on integers), and an incredibly
small stack space (on the order of 256 bytes
) - Good luck implementing SHA256 under those conditions.
Folding@Home made a client for ATI 1900 cards wich ran on DirectX 9. Yup, science computing on DirectX 9.
Back then OpenCL didn't even exist, not even CAL (CAL is like CUDA for ATI, supported since ATI 2000 if i am right)