Re: Hmmm... @J.G.Harston
That is true, but for volume data moves was mitigated by DMA from disk directly into memory-mapped buffers in the process address space, using the UNIBUS address mapping registers, which allowed raw DMA transfers to addresses outside of the kernel address space.
Of course, not all PDP11 models had the UNIBUS (or, I presume a similar QBUS) feature, but pretty much everything after an 11/34 would have. I had an unusual 11/34e that also had 22-bit addressing, which made it much more useful.
Biting the hand that feeds IT
