Matt BlazeMay 3, 2023
And speaking of telephone mischief, here’s a Dianatek model 041 pen register, designed for use not by law enforcement, but by telephone companies. The telco security department would hook this up to your line (at the central office) if you were suspected of making harassing calls or otherwise misbehaving with your service. It also detects signals used by blue boxes, despite being made well after they were obsolete. Resembles a movie prop bomb that starts a short countdown when you open it.
Show threadMatt BlazeMay 3, 2023
The main difference between this and the pen registers used by law enforcement was the usage model. This is a suitcase designed to be left at the central office, producing a daily printout on paper tape. The pen registers used by police provide a real-time link back to the investigators’ wiretap plant, where they are immediately alerted any time the target uses their phone.
Show threadMatt Blaze
Physical pen registers for analog phone lines are mostly (but not entirely) an obsolete technology at this point. Aside from the diminishing importance of analog telephony, wiretapping and dialed number recording features have mostly moved into the phone switches themselves (helped along by mandates in the Communications Assistance for Law Enforcement Act).
May 4, 2023 at 1:50amWeb