Macbook digital/CAT interface?

Hello all,

I am having some issues setting up my Macbook (non-Pro) to play nice with my digital/CAT interface.
Here's the hardware:
Macbook (OS 10.6)
G4ZLP Dual channel interface (older model, w/USB for CAT & 2-plug set up for digimodes)
Yaesu FT-990 (v1.3)

The Mac has a single port for input/output on the soundcard, which I was attempting to overcome with an inexpensive (read: cheap) USB adapter. The adapter has good reviews, mostly from people using it in audio applications (converting LP's to digital, line-in for musical instruments, etc.), but I have no other feedback for ham-related applications. Anyway, I did a little experimenting, and found that the 'ZLP seems to get the audio to the Mac direct, but not so well thru the adapter. So I guess that's an issue. I was trying to hold off on spending the $35 for an iMic adapter, but that may be the best answer.

In any case, there's still an issue with rig control. I am trying to run RUMLog, but I seem to be having trouble getting it "talk" to the '990. The software shows the '990 in the compatible rigs drop-down, but the best I can do is get it to key the rig continuously. I'm sure this is something I'm missing, and I'm hoping someone can shed some light on this for me.

Incidentally, this set up worked FB when using it with my old Dell D610 laptop. Of course, getting it that point wasn't without lumps of it's own...

I appreciate you all taking the time to read this, and I hope you may have some encouraging news for me in reply.

de Tony, W3FLH
73

(Also posting in the Digital Modes forum...)