On 07/08/2012 11:54 AM, G ran hling wrote: Just to "point on the nitty gritty details" To my knowledge; M+ will run on 11/23+ but not upon 11/23 ! (22 bit adressing required). This is not quite true! Most KDF11-A (dual-wide, non-"+") 11/23 CPUs DO in fact support 22-bit addressing. It is a common misconception that all dual-wide 11/23 CPUs only have 18-bit addressing. It is only the early revs of the dual-wide board that are limited to 18-bit addressing; prior to Rev C. The 11/23 was a very popular system in its day; DEC made a LOT of them...the vast majority of the boards you'll see in the field are Rev C or later. -Dave -- Dave McGuire, AK4HZ New Kensington, PA