thanks to those who responded to my question about using max/msp with the usb to serial adapter pololu USB01A. Jeff Mann forwarded this solution, which is actually a method for a GSM-USB cable that uses the same chip as the pololu (http://www.agri-vision.nl/CMS/index.php?option=com_content&task=view&id=32&Itemid=49). i used the Mac Developer Property List Editor to edit the info.plist file in the driver extension folder. so i now have the max serial object recognizing my device/port:

# Look in the System Profiler (Aplications/Utilities) under Hardware/USB which type of interface is used for the cable:

[e.g.] usb data cable:

Version: 1.00

Bus Power (mA): 500

Speed: Up to 12 Mb/sec

Manufacturer: Silicon Labs

Product ID: 0x10c5

Serial Number: 0001

Vendor ID: 0x10ab

# Here we see that this is indeed a Silicon Labs interface.

# Download the Virtual COM Port (VCP) driver from the Silicon Labs website (http://www.silabs.com/) The CP210x USB to UART Bridge Virtual COM Port (VCP) drivers are required for device operation as a Virtual COM Port to facilitate host communication with CP210x products.

# Install the driver by double clicking the SLAB_USBtoUART Installer [http://www.silabs.com/tgwWebApp/public/web_content/products/Microcontrollers/USB/en/mcu_vcp.htm]

# Unfortunately the standard product and vendor ID in the driver are wrong. So you have to put the Product and vendor ID obtained from the System Profiler, as explained above into:

/System/Library/Extensions/SLAB_USBtoUART.kext/Contents/Info.plist

# Open a terminal session

# type: sudo kextload /System/Library/Extensions/SLAB_USBtoUART.kext

# type: touch /System/Library/Extensions

# type: ls -al /dev/tty.SLAB*

# You should see the comport:

# crw-rw-rw- 1 root wheel 9, 8 Oct 18 08:32 /dev/tty.SLAB_USBtoUART

# Now you are ready to use your new serial port.