I was reading this old thread and saw this program, I don't know if it's of use yet, but give it a go
http://mac.softpedia.com/get/Drivers/TabletMagic.shtml
TabletMagic description Download
Open Source Mac OS X driver and control panel for serial and ADB Wacom tablets in Mac OS X. This project intends to expand to support other obsolete tablet brands. A full C++ tablet daemon and prototype control panel are already implemented, KEXT planned.
You see, I've got one of those old Wacom ArtZ-II tablets. The 12x12 one. It's huge, with a glossy surface and a really nice feel. I bought this beauty the same day I got my first Mac. Yep, this tablet and me, we've been through a lot together. So you can imagine our sadness when we learned that Wacom had abandoned us.
I groused about it and joined the chorus of voices calling for Wacom to support our beloved tablets, but they wouldn't budge. Undaunted, I visited Wacom's web site and downloaded every PDF and code sample they had. And they had a lot. In fact they even have new documentation explaining how to make Mac OS X programs understand Wacom-style and Apple-style tablet events. Very helpful.
From Wacom's documentation I was able to build a REALbasic program to interpret tablet events. More recently I learned from a reliable source how to send complete tablet events to the system and chopped together a daemon in C++. With all the pieces in place the TabletMagic Project was finally brought into the light.
Is TabletMagic Really Magic?
The short answer, no. Just the practical kind.
The Keyspan USA28X serial adapter communicates reliably with the Wacom ArtZ-II tablet at both 9600 and 19200 baud. This places no stress whatsoever on the USB system. 19200 baud - or 19.2 K per second - is very low bandwidth compared to the full potential of USB 1 (1.2 Megabytes per second). Wacom tablets can communicate at the full speed they were designed for -- and they do so very well in Mac OS X.
Mac OS X has really good built-in support for serial ports. Apple follows a standard called POSIX (Portable Operating System Interface) which provides a strong yet simple model for I/O. Because of the proven viability of this standard, Mac OS X will always have excellent OS-level support for serial devices - including all "legacy" devices like Wacom tablets. All any serial device needs to work with Mac OS X is a compatible connector and the software to drive it.
What's New in This Release:
· Basic multi-monitor support. Applescript to "renice" the daemon.
· Changes: Daemon init changed to account for a potential bad startup message, taking a cue from the linux-wacom project.