"e.stiebler" <emu at e-bbes.com> wrote: Indeed. If we talk $200 just for the board, and then you still have do develop the firmware, then $200 for a actual, already tested and proven SCSI controller is cheap. And new SCSI disks can still be bought as well. And while not dirt cheap perhaps, they are still not that expensive. Especially since you are not interested in several hundred gig drives for a PDP-11 anyway. Someone else asked about differences between a RQDX1 and RQDX3, from a software point of view. There is none, except in the irrelevant parts, such as the identity given by the controller, and version numbers and so on. The controllers are both MSCP. In fact, they are no different (either of them) from a KDA50, or UDA50 for that matter. Or any other MSCP controller. That's the whole point of MSCP. The controller always present the same interface to the computer. What it does on the other side is hidden. So, in fact, the device driver is the same for all these controllers, in all operating systems. MSCP is a great concept. Just wish it had survived. But, as with many DEC designs - they were technically wonderful, but they weren't PC. And PC became the de facto standard. No matter how lousy the hardware was/is. Johnny