This is great. I follow a site called Modern Mechanix, which features old advertisements and articles in the fields of engineering, technology and science. Some of them go way back to the late 1800’s and early 1900’s.
My father started his career off in the 60’s at Bell Telephone so I decided to send him the link to a recent post on Modern Mechanix which featured an ad for Bell.
I asked him if he remembered the ad. Here was his reply:

Yikes, not only do I remember it, in 1965 I was one of the few AT&T “data” technicians who worked on diagnosing and resolving problems on the “Dataphone” pictured in the Ad. Actually, it was a real fun job (to me anyway). These phones operated at 2400 bps (bits per second). Among other things, you usually had to “condition” the copper wires in order to pass error free data. This involved inserting customized equalizers in the signal path to compensate for the specific frequency attenuation characteristics of the assigned copper line. Soon after I advanced to supporting high speed/wideband data customers which introduced the then incredible transmission rate of 50kbps (50,000 bits per second). No one could imagine how there could possibly be a need or use for any higher data rates.

I think I understood a sentence in there somewhere.