This is a ‘built for Amdahl’ HP 1725A oscilloscope.
I bought this ‘scope maybe six+ years ago but just last year I noticed that there’s a curve tracer function tied to the intensity knob. The back states it’s an option ‘H01,’ which does not exist in any HP literature, and I couldn’t get any info from HP / Agilent. As far as I can tell there are no curve tracer specific inputs (option 101 includes the 1607A logic-state analyzer inputs), but if you look at the first photo, this was a unit built for amdahl.
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