On Jun 21,  9:56, Hauke Fath wrote:
> Subject: Re: MRG, ADB, serial console vs. PRAM time
> At 9:49 Uhr 20.06.1996, Steven Carlson wrote:
>
> >    The ADB wasn't desigend to deal with unplugging/replugging ADB devices.
> >It can't tell when new devices are added and removed.
>
> Wasn't it? As I wrote to Scott, I can
>
> o  boot my SE/30 without adb devices, plug them in and run, and even
>
> o  boot             "               , drop into MacsBug, plug the kbd in
>    and run.
>
> This tells me that there must be some provisions to deal with hot plugging.

Hauke,

I think you may be misinterpreting the results of your experiment. When the Mac
boots, it probes for ADB devices, and can load relevant drivers. If you add
more devices later, new drivers don't get loaded.

A simple experiment that will help to confirm this is to get a few different
keyboards (what, you don't have lots of different ADB keyboards lying around?),
boot the machines with all of them installed, run Keycaps, and try hitting keys
on the different keyboards. If you've got all the drivers, you should see the
layout in keycaps switch from one keyboard to the next. Then try booting with
one keyboard, and adding another, the layout will stay fixed, the system has no
knowledge of the new keyboard. It does recognise your keypresses, but they
appear to be coming from the keyboard that was connected at boot time.

I think the eplanation for your observations is that when the ADB probe at boot
time doesn't find any keyboards or mouses, it loads some default set of
drivers, thus accounting for your ability to attach these devices after boot -
They aren't actually being recognised anew, they are just being accounted for
by the drivers that were loaded at boot time.

Bernard.