At 01:00 AM 9/17/02 -0400, you wrote:
>On Tue, 17 Sep 2002, Carlos Murillo wrote:
>> The machine thinks that there is a floppy disk in the superdrive
>> constantly; it is always trying to read the (empty) drive,
>> then the "This disk cannot be read; Initialize? Eject?" dialog
>> box shows up, I click on "eject" and it starts trying to
>> read the nonexistent floppy again.
>Something fried the disk controller. I did this to one of my SE/30s once
>by being cavalier about not shutting the machine off before connecting and
>disconnecting an external disk drive.
Ouch, I really hope that this is not the case; SE30's are rare
here in Colombia. I know that I haven't plugged an external floppy
to this machine in eons. So if it is fried, that came out of the blue.
I did another experiment: I unplugged the floppy ribbon cable and
turned the computer on. No more "...initialize or eject" dialogs.
I've been looking at the SE30 schematics
(
http://www.archaic-apples.com/index.php?category=Macintosh&subcategory=Sche
matics),
especially page 2 of the SCSI-SWIM diagrams, where the floppy
disk controller is depicted. I see that the RDDATA line in the
header is tied to the RDDATA _and_ SENSE pins in the controller
chip. I don't see any signal name other than "SENSE" that might
indicate if there is media in the drive. I also see that
all of the lines go through an "RCNET" pack before heading out
to the external floppy disk connector. I wonder if the problem
might be in this device... I'd like to wait for input from you
guys before I turn on the soldering iron.
>I suppose it goes without saying that the floppy controller is not a
>standard part.
Not socketed, either :-( .
carlos.
--------------------------------------------------------------
Carlos E. Murillo-Sanchez carlos_murillo_at_nospammers.ieee.org
Received on Tue Sep 17 2002 - 07:55:01 BST