Subject: Re: MRG, ADB, serial console vs. PRAM time
To: Hauke Fath <saw@sun0.urz.uni-heidelberg.de>
From: Monroe Williams <monroe@teleport.com>
List: port-mac68k
Date: 06/20/1996 18:36:38
Hauke Fath writes:
>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.

I've always had good luck with hot-swapping ADB devices on my SE/30.
(I know that Apple warns not to do it, but I'm always careful to line
up the connectors carefully so I don't short things out.  Hey, isn't
running experimental operating systems a sign that you like to live
dangerously? 8-)  On later machines (7100, 7500), I've noticed that
[un]plugging devices while running resets the mouse tracking speed
to "annoyingly slow" (but not the same as doing it with the control
panel -- the driver seems confused).

My guess (and this is _pure_ speculation), is that the older ADB
drivers were written more defensively, and properly handled devices
being moved around, even though they didn't have to.  Since
hot-swapping isn't part of the spec, when the drivers for newer
hardware were updated/rewritten, they probably assumed that the
user would belive the user manual and power down before messing with
the ADB.

-- monroe
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Monroe Williams                                      monroe@teleport.com