Re: 5.25 Drive Timing Issues?

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

Sam Latella <powergs@macgui.com> wrote:
> Sam Latella wrote:
>> Sam Latella wrote:
>>> I've got several types of the 5.25 drives for the Apple II.
>>> 
>>> DuoDisk 5.25 drive
>>> Old style Disk II 5.25 Drive
>>> New style 5.25 drive
>>> 
>>> The issue is the 5.25 floppies I've created disk on the Duodisk and it
>>> works
>>> as well as the old style Disk II drive.
>>> However, when I use it in the newer style Disk II drive it does not boot
>>> up.
>>> The new style disk II will boot up original disks but not copied ones.
>>> 
>>> I think somewhere each drive is timing a bit different when copy data.. 
>>> How
>>> do I calibrate each drive back to the same settings?
>>> 
>>> Thanks,
>>> Sam
>>> 
>> 
>> 
>> Okay, I've got newer drive calibrated verified it with an old version of
>> Copy II plus drive speed between 198 and 202.  One set of new drive at 200
>> and the other at 199.  So we're good there.
>> 
>> Now, how do I calibrate the old Disk II drives, do I have to open them up
>> to
>> calibrate?
>> 
>> Thanks for all the help.
>> 
>> Sam
>> II
> 
> The last two drives are giving me a real pain.  An Original Disk II Drive is
> run at 170ms top speed using Copy II plus, and it needs to be between 198 to
> 202.  Can't seem to get this adjusted any higher?  Any thoughts?
> 
> The other drive is a clone Disk II drive and is running at 200ms using Copy
> II plus, but is not reading the disk.  What next?  Take it apart and clean
> the inside?
> 
> Thanks,
> Sam

Just for clarification, you mean that the drive won't run any *slower*.
I've never encountered a drive that couldn't be adjusted slow enough, but
drift in components in the speed control circuit could have this effect. 

Adding some resistance to the correct end of the speed adjustment pot
should correct this. 

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