I don't know if you understand the concept of memory partitions in RSX properly. No, I guess not. The usefulness of partitions in an unmapped system is easy to see - since tasks have to be linked (er, "TKBed") to run at a specific virtual address and all tasks have to share the same address space at the same time, you have to fit the tasks into memory. It's really the address space that's being partitioned as much as it is the memory. The concept is not unlike overlays. But once you have an MMU the whole procedure is pointless. Every task and every processor mode can have its own contiguous virtual address space. Nobody needs to share virtual address space with anybody else. And the mapping to physical memory is (for practical purposes) completely arbitrary and easily changed on the fly. What's gained by partitioning physical memory into fixed chunks that are allocated only to specific uses and can't be shared? Actually I thought RSX worked the way you described for M+ -> everything ran in a "GEN" partition, and the system just made as many GEN partitions as it wanted. Only if you were unmapped did you care which partition something ran in. Good idea. But there are SCSI controllers for the Q-bus, as well as the KDA50... I have both of those, but I'm not going to waste 'em on a 11/23! :-) Actually that's a pretty realistic attitude back in the day - these are more expensive mass storage devices and anybody who could have afforded them probably would have bought a faster CPU too. Bob