Re: Profile formatting

[shirsch@adelphia.net (Steven N. Hirsch)]

In article <37D907A3.7905@fz-juelich.de>, Patrick Schaefer wrote:
>
>Does anybody exactly know what software and which replacement EPROM you
>need? I have read many strange theories about formatting profiles but
>nobody had a detailed description.
>
>A few of the Profile Dealer Diagnostics disks should have survived and
>someone may have an image file of the firmware eprom. This could be
>uploaded to cabi.net. Perhaps a retired Apple technician is reading
>this...

A few years ago, a net accquaintance managed to unearth the majority
of the low-level formatting software.  I scrounged up a couple of
rom-piggyback Z8s and blew the EPROMs for them.  Personally, I've been
successful in reformatting a couple of 5MB ProFiles (though it's a
real pain-in-the-butt).

>The eprom plugs into a Z8-HD piggyback, doesn't it? 

Yes.

>We thought about repairing Profiles by swapping the ST506 mechanism or
>using the magnetic disks from a ST225 (class 100 cleanroom available,
>dust is no problem). But this would require a complete low level
>formatting, because all sync information has to be rewritten.

True.  I spent a bit of time trying to resurrect a 10MB ProFile with a
seized up HDA.  Turns out that the HDA from a Seagate ST412 is
identical, and the physical part of the repair was simple.  I was even
able to format it as a 5MB ProFile.  Problem is, I'm missing a
critical bit of code (IIRC, the 10MB formatter ROM image) to handle it
as "real" 10MB drive.  And, no, it's not as simple as searching for a
counter initialized to the number of tracks - been there, done that
<g>.

Someone would have to disassemble the Z8 code and hack it in that
way.  The way my free time goes, it will be during my retirement..

Steve