On Sun Aug 2 07:25:04, Pete Turnbull wrote: -- Snip -- You mean a "microPDP-11/23". The badge could be any of the microPDP-11 series, as far as I can see. -- Snip -- The badge appears to say "Micro PDP-11" with no suffixes. 11/73's and 11/83's and 11/93's have their own badges, assuming it wasn't an upgrade. I can't speak to the 11/53. My intent was to just list the most likely contents of the chassis, so the poster could get an approximation of what kind of CPU and device(s) to expect, although I should have been more precise, and said "PDP-11/23+ BASED system", since the "Plus" only calls out the quad board vs the dual. -- Snip -- If it were an 11/23 variant it would much more likely be an RQDX1, but that's very similar. -- Snip -- It was my (mis?) understanding that the later BA23's had the black buttons on the front panel, which to me would suggest the chassis has the FCO'd power harness, and an RQDX2, for RD53 support. But again, this is all speculation. For all we know, there could be an 11/83 in there, with a RQDX3, DHQ11 and SCSI. ;-) T