RH10 MASSBUS controller
From Computer History Wiki
An RH10 MASSBUS controller is a secondary storage device controller for the PDP-10, primarily for the early models (KA10 and KI10) which had the PDP-10 I/O bus as a standard bus.
It works with the MASSBUS disk drives and magnetic tape drives; up to 8 drives per RH10. It uses a DF10 Data Channel unit to perform DMA to main memory.
