Just to hastily follow-up and divert everyone's attention from my miss-fired reply (meant for Andreas and not the list), I found a recent bitsavers document which suggests the drives I have (Emulex SD590s) are not SMD drives as I originally thought, but DEC SDI (the host side is DSA a forerunner of MSCP?) - something I've never heard of before. Is anyone familiar with these drives that might know if the KDA50-Q controller is suitable? (EK-KDA5Q-UG-001_KDA50-Q_Users_Guide_Nov84.pdf) http://bitsavers.informatik.uni-stuttgart.de/pdf/emulex/SM9050501-A_SD59X_S… I get the impression these drives were really intended to be used with VAX-BI based systems and I will be out of luck trying to get them to run on a simpler QBUS MicroVAX system.