Apple /// Power Supply

[Steven Hirsch]

On Wed, 30 May 2007, Tony Duell wrote:

>> Wasn't there a similar issue with the hard drive low-level formatter, in that
>> it was never released by Apple - so you couldn't take a Lisa ProFile and
>> format it for a ///, and nor could you do drive replacement in the field -
>> instead the whole faulty unit presumably got sent back to Apple for repair.
>
> Wasn't there one drive -- and I think it was an Apple -- where you had to
> temprorially replace a microcontroller chip to be able to do a low-level
> format? And of course that specially-programemd microcontrolller was
> never avaialble to normal customers.

Yes, that would be the ProFile hard disk unit.  You swap in a "piggyback" 
Z8 MPU with special EPROM for the masked-ROM version and have at it with a 
special tool suite on the Apple ///.  I have resurrected several dead 
units by using the HDA assembly from a vanilla Seagate ST-506 (I think 
that's the one - from memory) with the proprietary Apple electronics.

Unfortunately, the collection of software I was able to get my hands on 
was missing the 10MB format utility so I've never been able to get a 10M 
ProFile fixed.

If anyone has a line on this, please contact me privately?  Ditto if you 
need the hex image or the diagnostic software.

Steve


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