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

I wonder how long it took them to "figure it out"? I seems that the family-plan dates to April 1969. June 1970 seems to be generally quoted as the introduction date for the PDP-11/20. And then June 1972 for the 11/10. My PDP-11 is labeled as "S-386" and dated 9/23/70, which I guess makes it fairly early in the production run (but I do wonder what the initial manufacturing rate was given the relative riskiness of this new architecture). Anyone have S# and dates for "plain 11" vs. 11/20-marked for comparison? -----Original Message----- From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Pontus Pihlgren Sent: Monday, February 22, 2016 3:27 AM To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: PDP-11/20 vd one that just says pdp 11 what are the date differences?? OEM? On Mon, Feb 22, 2016 at 03:25:36AM -0500, Paul Birkel wrote: ... Indeed, and it's just something I've "heard" so there might actually be another reason. /P