Recording: microphone vibration-> electrical signal-> amplification-> head coil->; Writing tape

Play: tape sensing-> amplification-> plastic filtering-> play; Amplification-> horn coil-> vibration sound.

2. Semiconductor memory recorder (pen)

Recording: microphone vibration-> electrical signal-> amplification-> analog-to-digital conversion/pulse->; Digitization-> write storage

Playback: memory->; D/A conversion/pulse->; Plastic filtration->; Amplification-> horn coil-> vibration sound.