From Wikipedia:

This page is written from a United States perspective, but most of the information here is identical for the original Terebikko. Differences will be pointed out where applicable.

Keypad of four “answering buttons”:

• 1 (RED)
• 2 (GREEN)
• 3 (BLUE)
• 4 (YELLOW)

• includes 'hook' button for picking/hanging up. (An output speaker.)
• includes speaker (handset audio)

• A speakerphone speaker (An output speaker.)
• A switch that toggles audio through the speakerphone or the handset audio.

• LED light (lit when device is on and volume levels are OK) – JP: “Volume Check”
• Power switch – JP: “Power Switch”

• Audio input (from VCR audio out, RCA jack input US, hard wired 3.5mm phono cable in JP)

See: Terebikko Video Titles

• https://archive.org/search.php?query=See%20Say%20Video%20Phone
• https://forums.lostmediawiki.com/thread/3385/mattel-say-video-phone-1988

• Muumipeikon upea lahja (Terebikko VHSrip)
• Bandai Terebikko Hello Kitty's Fun Food

• The Kansas City Standard
• https://www.tutorialspoint.com/digital_communication/digital_communication_amplitude_shift_keying.htm
• https://www.rtl-sdr.com/tag/ook/
• https://www.rtl-sdr.com/using-rpitx-and-an-rtl-sdr-to-reverse-engineer-and-control-ask-devices/
• https://www.rtl-sdr.com/wp-content/uploads/2016/12/ASK_erhard_e_tutorial.pdf
• https://www.usna.edu/ECE/ec312/Lessons/wireless/EC312_Lesson_23_Digital_Modulation_Course_Notes.pdf
• Line Coding for Digital Communication
• Serial Communication Protocol
• https://dabeaz.blogspot.com/2010/08/decoding-superboard-ii-cassette-audio.html
• Digital Modulation: One Bit at a Time

• https://dsp.stackexchange.com/questions/29946/demodulating-fsk-audio-in-python
• https://www.pythonforengineers.com/audio-and-digital-signal-processingdsp-in-python/
• https://www.embedded.com/the-goertzel-algorithm/
• https://docs.python.org/3/library/wave.html
• https://docs.python.org/2/library/itertools.html#itertools.islice
• https://stackoverflow.com/questions/2648151/python-frequency-detection
• https://stackoverflow.com/questions/29513126/python-understanding-difference-between-append-and-extend
• https://staff.fnwi.uva.nl/r.vandenboomgaard/SP20162017/Python/Audio/realtimeaudio.html