A Real-Time Digital Telephone Simulation on the Lincoln Digital Voice Terminal
A 1975 technical note from MIT's Lincoln Laboratory, written by Stephanie Seneff and catalogued by the Defense Technical Information Center, describing a real-time digital simulation of telephone degradations for military research. The pictures are plain engineering diagrams: a small hand-drawn axis-and-waveform sketch and a block diagram of signal-processing stages, with boxes, arrows, sine and cosine blocks, and labelled filters, useful to a designer as an example of schematic linework and clean, minimal flowchart layout.
