Re: SuperDrive Doesn't Work on PC Transporter

[supertimer@aol.com (Supertimer)]

"Bryan Parkoff" <BParkoff@satx.rr.com> wrote:

>    It seems to be strange that SuperDrive is not working toward
>TransDrive's connector that is reading and writing directly from PC
>Transporter.  Second SuperDrive is connected to Apple controller card
>directly.  I can be able to format SuperDrive through Apple controller card
>directly, but it fails through TransDrive.  Please explain what is the
>difference and why it doesn't work through TransDrive.

I had this combination too and basically it boils down to this:

The PCT's on-board PC floppy controller expects a PC floppy
drive.  The Superdrive is not this.  The Superdrive requires an
IWM or SWIM based controller.

The PC Transporter can format any disk as MS-DOS.  It
can format a regular 800k IIGS drive in MS-DOS.  However,
the encoding of such a disk would be GCR which would
be unreadable on a PC.

The Superdrive with SuperDrive controller combination,
however, is capable of writing BOTH GCR and MFM.  So
all the PC Transporter knows is that it is writing MS-DOS
to the Superdrive.  The Superdrive controller encodes this
in MFM and presto, you have a disk that can be read on
a PC.

Similarly, if you have a Transdrive on your PCT in Apple
mode you can write ProDOS disks to it BUT such disks
would be encoded in MFM, not GCR.  Because of this,
the disks will be unreadable on a normal Apple II drive
even though it is ProDOS.

In order to read a disk, BOTH the formatting AND the
encoding have to be right.