2006-07-20 10:03:35 UTC
uses MultyMedia Cards.
So what, you'll ask. There is already a CF interface.
Yes and no. My toy has a small AVR microcontroller on board and 2 modes of
The trivial mode simply interfaces the MMC to Apple as yet another ProDOS
The fun starts with the "smart" operating mode. The device looks to Apple as
a Disk ][ controller.
So Apple happily reads nibble images as if they were real 5 1/4" floppies.
This allows using
images of DOS 3.3 disks or any other .nib images. For example a couple of
games that do not
use DOS work fine.
The software is not quite finished: I need to add an application that will
run on Apple
and select one of many .nib images to use. My prototype just uses a single
image, but that is
not very difficult.
The firmware can use a lot of improvements too. Currently I feed Apple a new
byte every time
it asks for one instead of changing it every 32 msec. Seems to work for
quite a few images, but
won't work with many protection schemes.
The big question is is there any interest in this device? If there is, I can
make a small production
run and offer for say $100. If not, I'll be the only owner of the only
The board has an AVR micro and a CPLD for fast interfacing. Originaly I
though that an AVR
running at 16 MHz is fast enough to do everything in software, but it is
not. In addition the
CPLD acts as a perfect 5v to 3.3v converter - MMC uses 3.3 V. I can add an
to make this card bootable. Currently I boot from a real disk and DOS can
see the other
"disk" in another slot.
The MMC card can have up to 4 partitions. Some partitions up to 32 MB can be
as ProDOS volumes and one can have any number of .NIB images.
Future driver will be able to see 2 images at once as drives 1 and 2.