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Funny new Bug (or is it a Feature?)

avw

6502
Today a friend of mine tried to work at one of my G4s, a 733MHz at MacOS 9.2.2. While he was heavyly klicking around, opening Classilla and Acrobat 5 at the same time as XPress, he got a reboot alert box. You know one of these System 7 style ones, where the reeboot button is not drawn at the screen because the mac is frozen before he can draw the box to end. ;)

But – and now hold on:

Inside this alert box, there seemed to be a console. Maybe the open firmware? We could type in, delete, etc. sadly I am not familiar with OF so I had no possible command at hand. We also couldn´t reproduce this behavior, …

 
Did it look anything like this by any chance?

screenshot20100523at115.png


I can't remember what the official term for this is, but I can easily invoke it on my machines by hitting the Interrupt button (on machines equipped with interrupt buttons anyway).

 
Exactly that´s it iMac600! Only difference was that it is 9.2.2 So we acessed the debugger ;) ok, ... But what exactly is the normal and reproducable way to get there at G4s?

 
Command+(keyboard) Power Key, from memory? I'm sure someone will correct me if not.

On older Macs with a hardware interrupt switch, hitting the switch would bring up the debugger.

Once you install MacsBug, it replaces the little white box with a much more fully-featured version.

MacsBug would actually be called MACSBug, since it is actually Motorola's Advanced Computing Systems debugger.

 
Do G4s have the interrupt switch? I believe some blue/white G3s do, it's one of the two little buttons below the power button. The one that sticks out is a reset switch and the one that sticks in a little bit is an interrupt switch, as far as I can recall.

I do not, however, recall what the interrupt switch on a G3 would do, compared to what it'd do on a 68k Mac that has it.

 
Yep, Yikes, Sawtooth and Gigabit G4s all had interrupt switches, I'd hazard a guess that Digital Audio would too. Not sure about QuickSilver or MDD though. Cory's right, the concave switch is the interrupt switch, the convex one is the reset switch.

As for what it does, under OS 9 it would do the same as any other vintage Mac, bring up the debugger. Under OS X, if I recall it performs the same task as the reset button, resetting the machine.

 
I wish my MDD had a reset switch, it would be significantly more convenient and less hard on the system than having to hold down the power button to force a power down only to power right back up again.

 
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