Re: DISK ][

[swtownsend@hotmail.com]

  I have a few spare Disk ][ interface cards for the Apple II, if that
would help.
swtownsend(at)hotmail.com


On Mar 6, 2:31 pm, "Michael J. Mahon" <mjma...@aol.com> wrote:
> Roger Schmidt wrote:
> > Has anyone ever made like a DISK ][ to another interface. I have read
> > some of the documentation on the net and cant see why it isnt
> > possible?!? Or am I just kidding myself?
>
> Not everything is possible.  It is possible to design an interface
> (typically based on a microcontroller) to read normally formatted
> Apple II disks.  It is not practically possible to design an
> interface (without a cycle-accurate Apple II driving it) to read
> arbitrary copy-protected Apple II disks.
>
> Splitting the difference, it is possible (and practical) to build
> an interface that allows the reading (and writing) of *many* copy-
> protected disks, as well as normal ones.
>
> Most such designs put a lot of the work into the host machine's
> software (just like the Apple II).  The Catweasel card is an early
> "universal" disk controller, though its Apple II support is meager.
>
> Various Apple II "emulator" cards for the IBM PC (ISA interface)
> could read and write Apple II disks, which they did by essentially
> implementing an Apple II and its disk controller on the card.
>
> Reviewing Sather's description of the Apple II disk subsystem will
> give you some insight as to why a general adaptation to another
> machine is extremely difficult.
>
> > Where can i get a schematic of the DISK][ interface card?
>
> The DOS Manual contains schematics of both the disk drive (a much
> simplified Shugart SA 390) and the Disk ][ Controller, a Woz design
> of real finesse.
>
> > Does anyone have a bin or decompile of the PROM on the interfacecard?
>
> There are two PROMs, one is the boot PROM and the other is the
> state machine PROM that does synchronization and data separation.
>
> Check out the chapter on the Disk ][ and its controller in Sather's
> Understanding the Apple II or Understanding the Apple //e.
>
> PDF versions are available on the web.
>
> -michael
>
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>
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