Bill Garber wrote:
"Sheppy" <the.sheppy@gmail.com> wrote in message news:07dfdd15- 96dc-4455-ab5e-3dbebc3e7a01@z11g2000yqz.googlegroups.com...Does anyone have details on how to go about modifying a drive to handle flippy disks correctly? Almost every disk I have is flippy, so modifying my drive is likely to be something I'll want to do (or, more likely, find someone else to do for me, since as many of you know, hardware and I don't get along well). SheppyI don't know if this board will operate one, but one of the Catweasel forums says to get a 360K drive, which is capable of single sided disks by nature. I believe I may have one fairly handy and I will give this a try sometime this afternoon.
Unfortunately, any drive will still fail to generate index pulses if a disk is flipped. I don't recall where I read it, but a couple of years ago, I found a web article on modifying a drive to generate index pulses when a disk is flipped. It presented two methods. One was installing a second LED- phototransistor pair on the other side of the drive, ORed with the existing one (just paralleled with the emitter and collector), so that index pulses were generated regardless of disk side. The other method injected pulses from the drive motor (I believe using a Hall effect pickup) instead of real index pulses. The second method is a lot neater, though you give up the ability to tell whether the disk is actually spinning when the motor is turning. ;-) I'll see if I can find it again...or maybe one of you can. ;-) -michael NadaNet and AppleCrate II: parallel computing for Apple II computers! Home page: http://home.comcast.net/~mjmahon "The wastebasket is our most important design tool--and it's seriously underused."