thinkpad audio

[mykle hansen <mykle@Vinton.COM>]

hi.  for purely hobbyist reasons, i am wanting to hook some real
microphones to my thinkpad 760 and do some live digial recording, 
ideally in stereo.

i'm a bit puzzled by the input connector on the TP760 -- it seems
to take an 1/8" stereo plug, but it also has a sheath around the
outside that makes it able to accept -- at least physically --
a male RCA plug.  the meager documentation describes this as a
combination micropohone and line-in jack.

does anybody know, or have leads on, where i can get the technical
specifications for this connector?  expected voltages, impedence,
what kind of weird connector i should use, etc?  

thanks for any help,

-mykle-