Re: fix daisy chain

[Rubywand <rubywand@swbell.net>]

chuck_m_s57@my-dejanews.com writes ...
> 
> I know this question has been ask before but i've never seen the answer.I
> have two apple II 3.5 drives model no. A9M0106 one will daisy chain and the
> other won't.I hookup the 3.5 drives first in line like I've read you
> should.The other drive did work but I did what it say not to do on the cord.I
> didn't power off the computer before disconnecting and connecting drives.It
> didn't short anything out it still work as a single drive.The computer just
> doesn't read any drive on the otherside of it.There must be some kind of on
> board bios that got erased.Is there any way to reprogram the daisy chain?
> 
 ....

     The reason for not connecting or disconnecting drives while the power to
them is ON is that, in the process, you can create undesirable circuit paths.
For example, some signal input line to a drive might briefly become part of the
+12V power circuit.

     It is not clear from your description exactly what you did and what still
works. _If_ both of your 3.5" drives and one of the 5.25" drives work okay,
your GS disk controller IC is probably fine. (There is no erasable BIOS to
reprogram.)

     If you have a 5.25" drive connected and it works and you plug in your
second 5.25" drive and the new drive does not work, the most likely explanation
is that an input on the second 5.25" drive is damaged. If the second 5.25"
drive does not turn ON at all, then, probably, it's Drive Enable input was
zapped.



Rubywand