PDP-11/20 vd one that just says pdp 11 what are the date differences?? OEM?

[COURYHOUSE at aol.com]

Ok  then it  definitely  defines   the  date  then of  a unit.
 
eons  ago  when I first had started compute exchange in Phx  we  had  one 
that just  said  pdp -11 as I   remember  it came from Sandia  Labs.
 
 
Currently  we  have a  11/20 Ed#  smecc.org 
 
 
In a message dated 2/22/2016 1:12:16 A.M. US Mountain Standard Time,  
pontus at Update.UU.SE writes:

The  PDP-11/20 was the first PDP-11. I believe the number was added when 
the  other models came out, to discern them.

/P

On Mon, Feb 22, 2016  at 03:03:17AM -0500, COURYHOUSE at aol.com wrote:
> PDP-11/20   vd  one that just says  pdp 11  what are the  date  
differences?? 
> OEM?  was one  version  for customer  and  one  for OEM?
> THANKS IN ADVANCE
>  
>  Ed#  
>  
>