Re: 1571 (128D) spindle speed adjust?

From: Francesco Messineo <francesco.messineo_at_gmail.com>
Date: Thu, 21 Dec 2017 09:26:44 +0100
Message-ID: <CAESs-_wOhYbf518Q24JYqXZCkjtWwwC_8PGnaDBm=uoRTCgnbg@mail.gmail.com>
On Thu, Dec 21, 2017 at 9:17 AM, silverdr@wfmh.org.pl
<silverdr@wfmh.org.pl> wrote:
>
>> On 2017-12-20, at 14:32, Francesco Messineo <francesco.messineo@gmail.com> wrote:
>>
>> Hi all,
>> is it just me or there isn't a clear way to check and adjust the
>> spindle speed on an internal drive of the 128D?
>
> Adjusting may be tricky but checking can be done for example by using a strobo-pattern similar to what's been standard on earlier 1541 mechs. Or if your drive can still read, you should be able to run a small prg that verifies the interval a specific sector's sync mark is detected. I remember I once wrote (actually rewrote with timer adjustment) something like that for 1541.

I've tweaked a bit the pressure spring on the top head (side 2), the
drive now formats and reads (still marginally, but directory is always
ok)  the 1541 disks, so side 1 works. Side 2 still doesn't format
(well, it formatted once in 20 tries) and doesn't read.
I think it's the top head position that's wrong.
When formatting a double side disk, this firmware makes the first 35
tracks on the side 1 (bottom) then seeks back to first track and
formats the side 2 35 tracks. When seeking back for side 2, it usually
stops formatting.
Wirings on the top head seems ok, but I'll check also that.
Thanks
Frank

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Received on 2017-12-21 09:00:42

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