Re: firmware for the PseudoDisk

["Alex Freed" <alexf@mirrow.com>]

"Michael J. Mahon" <mjmahon@aol.com> wrote in message
doKdnQwUuPjdo8_YnZ2dnUVZ_hydnZ2d@comcast.com">news:doKdnQwUuPjdo8_YnZ2dnUVZ_hydnZ2d@comcast.com...
>
> Apple's SCSI cards implement a Mac-style partition table.
>
> CFFA implements "hard" partitions set by the controller, with
> no partitioning table.

How do you normaly put stuff on the CFFA card? On the Apple itself,
like a hard drive?

> > Same way as Apple emulators use .hdv images on my NTFS drives.
>
> OK, so the ProDOS file system is embedded in a FAT file.
>
> This approach essentially replaces Apple partitions with
> FAT files, so only a single FAT partition is needed, with a
> file for each Apple "partition".

Exactly. Which is great for using a PC to fill up the card.

> Of course, the FAT files
> may not remain physically contiguous, so multiple levels of
> block mapping are required (Apple to FAT and FAT to physical).

It's relatively easy and fast to map ProDOS image's ralitive sectors
to phisical sectors on the SD card. For nibble mode we only need
a list of pointers to 13 blocks that represent a "track".

-Alex.