Ever wonder what happens behind the screen when you hit backspace or hear a computer bell chime after a task completes? In this episode of pplpod, we explore the fascinating, outdated world of ISO 2047, the 1975 standard for graphical representations of 7-bit control characters. Before modern high-resolution displays, engineers had to visualize invisible commands to debug the noisy analog lines of early data networks. We journey through tech history to examine the Teletype Model 33, a machine that used physical spinning drums to answer the query: "Who are you?" By unpacking the graphical representation of control characters, we reveal the legacy computing logic that still dictates how our keyboards function today. From the "digit ...