> 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