American Telecommunications Corp TonePulse Converter
PCB Photos
Power Supply & Line Interface
Logic #1
Logic #2
Tone Detector
Component Information
Amphenol Plug/Socket
Schematic
The following is a schematic for the 204 series TonePulse converter, but from what I can tell, at the level of detail provided in this schematic, it's functionally identical to the 104. The 204 seems to be an optimization of the 104 design.