Re: Rarest Card

[e p chandler <epc8@juno.com>]

On Oct 19, 3:03 pm, "Michael J. Mahon" <mjma...@aol.com> wrote:
> rhohler wrote:
> > The NuMustang discussion got me thinking.  What is the rarest Apple II
> > card today?  Of course, prototype cards are limited and rare but what
> > production card.  I would bet on the Transwarp II card or something.
>
> I have some 128K bubble memory cards that emulate a Disk ][ with
> somewhat less capacity.  They were made by Helix Labs, and were
> intended to provide non-volatile storage for Apple II's used in
> harsh industrial environments.

I once considered using one of these in a project which buffered data
from a multi-channel analyzer. The problem with the disk 2 is that it
disables interrupts ([perhaps it was DOS 3.3....) The commercial
solution to the problem used a clock card which itself generated
interrupts. My idea was to write the data to bubble memory instead of
to disk.

As far as rare cards go, I did see a demo at a club meeting of an
modem card that had a number of special abilities (no I don't live in
silicon valley). It was never produced because it had a tone generator
built in which would have turned the Apple into a blue box (yes I know
the guys at MIT did it first!).

---- e