Well, Thanks to an idea that the RT-11 "Software Support Manual" gave me, it looks like I solved my problem. I copied the DU device handler to DA, and set the CSR's and Vectors such that DU is the Viking, and DA is the RQDX3. It has now been 30 minutes since I looked at the floppy sitting in the RX50 and the system hasn't crashed. This has the added benifit of allowing me to have DU0-DU7 for the Hard Drive partitions and DA0 & DA1 for the floppies. Cool, can't decide if I want to takle adding in some Serial Ports, or work on getting the DEC Pro380 up and running. I highly recommend working on Classic Computer projects as a method of staying awake, nice to be using them to stay awake instead of loosing sleep because of them :^) Zane | Zane H. Healy | UNIX Systems Adminstrator | | healyzh(a)aracnet.com (primary) | Linux Enthusiast | | healyzh(a)holonet.net (alternate) | Classic Computer Collector | +----------------------------------+----------------------------+ | Empire of the Petal Throne and Traveller Role Playing, | | and Zane's Computer Museum. | | http://www.aracnet.com/~healyzh/ |