man ddb, if you mean the kernel debugger: ddb may also be activated from the console. In general, sending a break on a serial console will activate ddb. There are also key sequences for each port that will activate ddb from the keyboard: amiga <LAlt>-<LAmiga>-<F10> mac68k <Command>-<Power>, or the Interrupt switch.
Thanks. On mac68k, I cannot get the debugger to come up from the serial console. Also, my Quadra 605 machines do not have an interrupt switch. Twice I've tried the left alt & Amiga plus F10 keystroke, and gotten nothing with GENERIC kernels.
I suppose the next thing is to try a Quadra 800 I have since it does have an interrupt switch...
Thanks, John