Re: Problem with Universal Disk Controller

[steve.howell@altium.com.au]

Hmm.. this nice piece of gear isnt just hardware. I recall we put a
lot of these units into service when I worked at Uni. It was quite a
treat not relying on the what felt like an infinite floppy swap to get
app's up and running on fat macs, abeit at quite a cost, but cheaper
than lisa's.

The apple II SWIM based UDC controller was designed to interface to
such a unit - ie, most apple products (Mac's and II's) with either a
IWM or a SWIM. At the physical layer it is a correct match, ie
physically electrically compatible. Operation between the II with an
apple UDC and the HD20 is restriced at a higher firmware or software
level, which im currently looking into. But I am finding hints in both
the firmware of the controller and the firmware of the rodime
mechanism. Why am I doing this? If I had a reason, it wouldnt be a
hobby.

Electrical violence?! :) Yep. right.

steve.



On Mar 7, 8:34 am, "Michael J. Mahon" <mjma...@aol.com> wrote:
> steve.how...@altium.com.au wrote:
> > It plugs up ok - even polls a few times - but im not sure if the
> > firmware of the card is expecting a hard disk sector to respond.
>
> You may have done some electrical violence to the drive and/or
> controller.  This controller was not designed to attach such a drive,
> which was very specific to the early Mac.
>
> That's why it's valuable to early Mac users, but just "hardware" to
> anyone else.
>
>
>
>
>
> > A shame really - it would have been interesting. I expect I wont be
> > selling this unit, but more carefully taking it apart to take another
> > snap shot at what apple was designing with this sort of technology
> > back in 1985, and poping it up on my webpage - maybe even extracting a
> > bit of info to get any aspects of it into the FPGA domain. This
> > particular design is loaded with a lot of European devices (including
> > a Rodime hard disk, whom, mr rodime, the lucky bugga, now lives off
> > royalities for the HD technology almost exclusively) - so with all
> > these euro bits, it really looks like a corke project.
>
> > Beautifully made, as was all of apples stuff of that era.
>
> > steve
>
> >> I would not even attempt it. An HD20 is worth a lot to the right Mac
> >> crowd. You can probably get enough money out of it to cover one of the
> >> variety of other mass storage solutions available today (CF, Focus,
> >> SCSI, etc.)
>
> -michael
>
> ******** Note new website URL ********
>
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