My 2400c required the 'resistor mod' to enable Cardbus; no yellow wires in sight for mine 
It's working fine now with a MacAlly USB card and Orinoco Gold wireless card in both slots. Mine is specced to 240Mhz G3/112MB RAM (bought from YourMacStore, cheap!), 40GB HD - a beast for it's diminutive size!
From what I read online, the TI chipset used for PCMCIA support in both PB2400 and PB3400 is definately Cardbus compliant, but the card cage is not - it's too slim to fit some cards. Hence it was disabled on the PB2400 but not the PB3400. Perhaps Apple never intended to release Cardbus-enabled notebooks until G3s were released?
Some more info:
http://www.wallawalla.edu/frohro/Cardbus/Cardbus.html
JB
It's working fine now with a MacAlly USB card and Orinoco Gold wireless card in both slots. Mine is specced to 240Mhz G3/112MB RAM (bought from YourMacStore, cheap!), 40GB HD - a beast for it's diminutive size!From what I read online, the TI chipset used for PCMCIA support in both PB2400 and PB3400 is definately Cardbus compliant, but the card cage is not - it's too slim to fit some cards. Hence it was disabled on the PB2400 but not the PB3400. Perhaps Apple never intended to release Cardbus-enabled notebooks until G3s were released?
Some more info:
http://www.wallawalla.edu/frohro/Cardbus/Cardbus.html
JB