what was the break point as far as manufacture dates between the 2? Ed# In a message dated 2/22/2016 1:25:31 A.M. US Mountain Standard Time, pbirkel at gmail.com writes: Which has always struck me as a bit odd, since the PDP-11 family was designed to be just that, a family. So you'd think that "marketing" would have kept that in mind when designing the first front panel label ... -----Original Message----- From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Pontus Pihlgren Sent: Monday, February 22, 2016 3:12 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? 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: differences??