a) At the moment, there's no CD-ROM, or other similar devices.
    Will that change perhaps in three years from now? ... perhaps it
will.

Right now there's the Chinook/Sequential drive if you can find one,
and it's still working. they're basically all ticking time bombs.
Design issues cause the controllers to fail.

(There's a rarity, lightning, thunder, sun and fog at the same time -
in Southern California. Lets see if I can finish this post.)

b) RAM Disks for the //c and IIc Plus.. counting both piggyback cards
and expansion connector cards there are quite a few of them.

http://apple2.info/wiki/index.php?title=RAM_Cards

1800 blocks? Everything there is a 1 meg card which is 2000 blocks,
1600 is an 800K disk, 1800 is an odd amount, sounds like an Amiga 3.5"
volume.  1 meg was the most the mass market ever saw for the inside of
the IIc as the sizing and chip density just didn't really allow for
more.

The original AE card was 512K - and there were some 256K cards as
well.

c) the IIc Plus I have- has an 40 meg drive within it and it's inbuilt
3.5" drive has been pushed to the outside atm. It also has a 512K RAM
card in it because it's small enough to allow for the cabling to pass
over it for the hard drive, and it's speed has been jacked up to 8MHz.
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