apple Lisa2. Any advice on non-working floppy drives?

[Terry Stewart]

Much obliged for the comments.

Actually I do have a logic analyser and a (borrowed) scope, so I can see if 
there is a pulse or a waveform.  Making sense of the latter is another 
matter entirely of course. (-:

> I assume you've checked the obvious -- that the spindle motor will turn
> freely by hand.

Yep!

> How do these things detelct that a disk is inserted? ....

Not sure Tony. I'm fair more familar with 5.25 inch drives.  I'll do some 
reading...

> This is a really silly comment, but I'll make it anyway. You are using DD
> (and not HD) disks, right? The point is that in some drives (certainly
> some erly Sony full-height osnes), the disk-insered sensor lines up with
> the HD-detect hole in the latter disk tpye, so if you load such a disk
> the drive doesn't notice it.

Actually not that silly.  I AM using a HD disk as a dummy disk just to see 
if it rotates and is spat out.  I hadn't considered the sensor lining up 
with the HD hole.  I actually don't have any Lisa disks at the moment 
(someone is sending me a MacWorks one).  You make a good point.  I'm sure I 
have got some DD disks tucked away somewhere so I'll try those before doing 
anything else.  If it's as simple as this, I'll be over the moon.  The 
previous owner said the drives didn't work though and (unlike me) he was a 
Mac man (hence should know these things, right? :-)  ).

> Be careful. I don't know if that manual covers the Liaslite/Sony drive
> system or just the origianl Twiggy drives, but I could well believe there
> are differneces between them.

Noted.  From the reading I've done so far, it seems to cover only the 
original Twiggy drives.  From what I've read though the Lisa 2 has the 
twiggy interface, and the Lisa Lite board allows the Sony 400k drive to be 
used with it.  As you noted, most of the lines seem to go straight through.

Terry