Re: Adding a second floppy drive to an Apple IIe

[Linards Ticmanis <ticmanis@gmx.de>]

On 05/05/2011 09:58 AM, Michael J. Mahon wrote:

> If it isn't the '125, it could be a dirty head, misalignment (not
> likely unless a drive has been dropped),

...or some unqualified person tried to align it with tools and/or
software that aren't up to the job, such as the ridiculous alignment
program on some CALL-A.P.P.L.E. disks. Hint: if you can help it, leave
the alignment alone, it's very easy to do more harm than good with that.

This might be too obvious, but check that the drive is actually spinning
the disk. Sometimes stiff, dry or broken belts can prevent that, or a
slipping belt can mean the disk is spinning far too slowly.

As for speed when the belt ISN'T slipping, I'd personally suggest not
using a special software to adjust it, but the strobe pattern on the
bottom of the drive mechanism. In case of the Disk II you'll have to
remove the bottom half of the case too (four more screws and careful
extraction of the cable), put in a disk, make the drive spin (e.g. by
trying to boot), then shine an AC fluorescent lamp on the bottom of the
mechanism, turning off all other lights if possible. If the speed is
right, one of the two patterns (which one depends on your mains
frequency, 50Hz or 60Hz) will seem to be standing still. On the disk II,
speed can be adjusted by the little screw that sticks out at the right
side of the smaller, vertical PCB inside the drive; but turn it in small
steps only, and do not try to adjust any of the other potentiometers and
trimmers inside the drive. If your mains frequency is reasonably stable
(which it is in most developed nations), the adjustment with the strobe
pattern is very exact, while some of the speed adjustment softwares are
a bit off because they used slightly wrong numbers for the Apple's
average clock rate. But the software solutions are still good enough for
everyday usage.

-- 
Linards Ticmanis