Is my ATA 100 hard disk going to work with my ATA 133 mobo? I've searched but all I can find is confirmation that the faster ATA 133 HD will work with the slower ATA 100 controller. Will the mobo and disk still negotiate an operating speed?
Yes that all works. Connecting PATA/33 or PATA/66 to PATA/133 controller will make that device run in PATA/33 or PATA/66 instead. So it just gets the highest speed either controller or drive can support.