Re: testing SFD1001 spindle speed

I don't believe scale matters, just the number of bars per revolution;
centering is also not super-critical.

I've had one stuck on a filing cabinet for decades and still use it
occasionally.

You do need a lamp that flickers at 50 or 60Hz though.

m

On Wed, Feb 12, 2025 at 9:01 AM Francesco Messineo <
francesco.messineo_at_gmail.com> wrote:

> On Wed, Feb 12, 2025 at 2:53 PM Gerrit Heitsch
> <gerrit_at_laosinh.s.bawue.de> wrote:
>
> >
> > You could make a photo of the strobo pattern from a 1541, print it and
> > glue it onto the spindle of the SFD-1001. Assuming the SFD-1001 also
> > uses 300 rpm, that should work.
>
> yes this works too, but you need to print it with the exact scale and
> center it as precisely as feasible on the spindle.
> I think I'll try first the index pulse method, I've written some
> programs when testing an 8250LP some time ago, I just need to find the
> tape where they were saved...
>
> Btw, all 5.25" drives use 300 rpm BUT the PC-AT 1.2Mbytes ones that
> run at 360 rpm in HD mode.
> Frank
>
>