Extended Memory Interconnect
From Computer History Wiki
The Extended Memory Interconnect (acronym: XMI) was a bus introduced with the VAX 6000 series of DEC computers to cope with increased requirements, e.g bandwidth.
The XMI bus started with the "+5V XMI-1" version which was developed to the "+3.3V XMI-2" version later on.
There was an upgrade kit option H9657-CU that takes a VAX 6000 Model 200, 300, or 400 system with an XMI-1 power system and upgrades it to a VAX 6000 Model 500 with an XMI-2 power system.
The upgrade adds +3.3 volt power, an XMI-2 backplane preassembled with bus bars and cables, and an H7206-B power and logic unit.
EK-650EB-UP-002 VAX 6000 XMI Conversion Manual describes the upgrade procedure.
