NewerTech FireWire 2 Go PCMCIA/CardBus Card Target Disk Mode?

All my searching seems to confirm my hazy memory that my olf NewerTech FireWire 2 Go card does indeed support target disk mode, but the old “hold T while booting” trick doesn’t seem to be working. Another shady part of my memory is that the key command was different, but what is it? Either Google is failing me, or it really isn’t online anywhere. Help?