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Weird: floppy disk not recognized by Finder

MikeatOSX

Well-known member
My PowerBook 170 has a weird floppy problem:

the PB can boot with any fitting floppy disk - even with system 6.0.8 disk from Macintosh garden. 

When I boot with it's hard disk and then put in a known good disk, Finder does not recognize, that there is a floppy disk: no sound, no floppy disk on the desktop. When I use Disk Copy and load a disk image, I can put in a disk which is written correctly and then ejected, like it should be. 

It's only the finder which doesn't see the floppy disk. 

I changed the floppy drive (still not the floppy drive cable): 

same behaviour. 

Any ideas please?

 

MikeatOSX

Well-known member
omg! 

It must be a software thing! 

When I start with extensions OFF, floppy disks are recognized as usual by Finder !

I unscrewed the PB so often.....

 

MikeatOSX

Well-known member
It's not so easy as I thought. I thought I'll solve this problem by de-activating several extensions and deleting several prefs in the prefs folder. No luck. 

Only Disk Copy 4.2 when started is able to eject a non Finder recognized disk. And of course disks are still recognized by Finder when extensions are disabled. 

Conflict Catcher checked all extensions and all are ok. 

So I have to do more extension testing nevertheless.  :O

 

MikeatOSX

Well-known member
I finally found the solution!  

In RamDoubler 2 readme file:

  "68030-based PowerBook and Duo users with 8 MB RAM in System 7.5, may experience the following if in 24 bit mode:

a. the PowerBook won't go to sleep when you shut the lid

b. the physical buttons for the monitor backlight don't work

c. the floppy drive doesn't work

Solution:  Install System 7.5 Update 2.0 which fixes these problems in 24 bit mode or turn on 32 bit addressing in the Memory Control Panel."

It's a very rare problem, which cost me hours of investigation. 

When booting System 6.0.8 with floppy disk on a PowerBook 170 (or PB 140), the RAM memory is switched to 24-bit mode.

If you later boot from the hard disk System 7.5.5, this switchover is not reversed, but must be manually switched to 32-bit mode again in the memory control panel.

Then the floppy drive works.  :)

 
Last edited by a moderator:

MikeatOSX

Well-known member
True. 

I even changed the interconnect board.  :-(

But I also changed the cover with the broken hinge mounts. 

So this PowerBook looks like new now.  ;)

 
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