Re: Adding a second floppy drive to an Apple IIe

[Michael J. Mahon <mjmahon@aol.com>]

Linards Ticmanis <ticmanis@gmx.de> wrote:
> On 05/05/2011 08:01 PM, Jeff Shanholtz wrote:
> 
>> No, it's an apple drive. I'd much rather get the apple one working
>> than the other off brand ones. I can try the fluorescent light
>> approach (I think we have one somewhere), although I'm not convinced
>> that a mechanical (speed) issue would prevent the other functioning
>> drive from booting (i.e. a mechanical problem in 1 drive causing an
>> electronic problem on the drive card and/or other drive). Admittedly
>> I'm not very knowledgeable about these drives though.
> 
> You're right, a speed issue wouldn't cause the other drive to fail. As I
> said the 74LS125 is still a possible villain. The failure mode you
> describe leads me to the assumption that the ULA 2003 might be more
> likely in this case though; its failure could cause one drive to hold
> the phase lines, so that the computer can't move the other drive's head
> any more. Also, your controller card might have a problem with two
> drives attached, or maybe your PSU might be failing and the two drives
> tax it too much (the latter isn't all that likely though).

Right--the deselected drive is all but powered down. 

It would take a shorted 2003 input to interfere with another drive, which
seems unlikely. 

(I'm responding as I'm reading this thread, so apologies for repeating what
others have said.  ;-)

> Do you maybe have another controller card, so that you can connect each
> drive to its own controller?
> 
> Also try plugging in ONLY the supposedly bad drive, does it work then?



-- 
-michael  -  NadaNet 3.1:  http://home.comcast.net/~mjmahon