[NTLK] Line in options

[Neal Trembath]

Yes, it's possible to attach an external mic.  The Newton is capped at 10 kHz mono recordings though (http://support.apple.com/kb/TA37220?viewlocale=en_US).

>From what I recall, the sound pref toggles between input sources: the mic circuitry (mic level) and the dongle circuitry (line level; cf., http://en.wikipedia.org/wiki/Line_level).  The dongle circuitry is accessed through the serial (dongle) port, through the internal slot (not the PCMCIA slots), or through the slot traces.  You'll have to find an adaptor (e.g.,  http://www.pda-soft.de/freedock.html, http://normalkid.com/collector/inter.html) or build one.  There are dongle circuitry schematics out there for building an adaptor.  Unless you want to use a preamp w/ your mic, I'd stick to the mic circuitry.

To plug an external microphone into the mic circuitry, you will have to hack: open your Newton, cut the mic wires, replace the Newton's mic w/ a mono, mini jack.  A mini jack will easily fit in the covered hole near the serial port.

There are plenty of places to buy inexpensive, stereo, mini jacks w/ contact breakers.  You can wire your mic input circuit to one line and your speaker output circuit to the other.  Whichever circuit you use more often w/ external devices (e.g., headphones, line out, microphone) should be wired to the ring.  When you plug in an external device, the breakers will temporarily disable your Newton's mic and speaker.  When you unplug the device, you'll have access to them again.  You can easily build/buy a stereo to split-mono adaptor.  (S)hadio(r)ack has a stereo jack w/ breakers that fits side by side w/ an overclock switch in the Newton's covered hole.  Cost for the project = ~ $5.

Good luck,
N