Texas Instruments 4000M - Manual (Page 81)

Microphone and Headphone
The following diagrams display where the microphone and headset plug into
the Portable CD-ROM Docking System.
Microphone and headphone connections
Audio Input
You can plug in external audio sources through ports on the Portable CD-ROM
Docking System. External sources may include:
T
Musical Instruments - Line in port
T
Tape players - Line in port
T
Mixers - Line in port
T
Microphones - Microphone port
4- 11