Re: davong a5xx hdd interface

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

marco oriani wrote:
> On 2011-02-10 21:05:17 +0100, wmeckling said:
>
> > On Feb 8, 6:19 pm, marco oriani <seekyoudrum...@gmail.com> wrote:
> >
> > > I've bits of a hard disk (mfm) interface for apple II. I got the apple
> > > card, the MFM drive, internal cables, external cable linking the drive
> > > to the apple but missing the case. I got three wires on the electronic
> > > board which should go together with the drive
> > >
> > > below an image of the system:
> > >
> > > http://www.digibarn.com/history/05-08-21-OpenHouse/DSC07217.JPG
> > >
> > > anyone has any idea if I have to supply voltage to the electronics for
> > > the drive?
> > >
> > > has any of you this stuff. I'd really like to get it running. I also
> > > got the system software.
> > >
> > > cheers
> > > marco
> >
> >
> > Marco
> > I had one of these drive years ago. As mentioned in other replies I
> > want to verify it is a MFM drive and it it does require +5vdc and
> > +12vdc. I think it is it a non standard interface between the
> > interface card and controller similar to SCSI but not quite and not
> > quite SASI either. The original drives were Dos 3.3 but maybe Prodos
> > drivers could be written. Do you have the S/W that came with it?
> > wm
>
>
> I've the sw, there are a couple of disk. one is for dos3.3 the other is 
> a cp/m installer.
>
> I've got a new drive for it but still I've to find how to connect the 
> power supply.

Well, with one wire ground, one +5v, and one +12v, it shouldn't
be too hard to figure out.

Ground should be obvious, with continuity to all the ground traces.
+5v should also be easy, with continuity to all the +5v pins of the
ICs.  The remaining one should be +12v, and should connect to very
few things, including the drive.

-michael

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