[Duo2400] Re: Duos and PC Cards

[Gregg Eshelman]

--- Dan K <macdan at comcast.net> wrote:
<clip>
> And now please step over into the 'NOT AT ALL WHAT I
> ASKED' department:
> I think it technically _should_ be possible to hack
> a PC card slot onto a 
> 2300's ATA bus, but again drivers (lack thereof
> actually) would probably 
> be the tripup. I recall one mad-Mac devising a
> flashcard adapter for a 
> PB150, with a little device to load some boot code
> or something to allow 
> the thing to boot from the flashcard.

The PCMCIA (Personal Computer Memory Card Interface
Association, if I recall correctly) originally set
a standard for a memory card bus that acted like
an IDE/ATA device. How that guy got the PB150 to boot
from a Compact Flash card was through a rarely used
(in PC systems) signal pin state that sets it up to
act as if it is an IDE hard drive instead of a
"generic" IDE storage device. The modification was
made on the IDE to Compact Flash adaptor.

That signal pin state is widely used in embedded
systems where all the software is stored on a Compact
Flash card or chip that interfaces like a CF card.

The failed iOpener "internet appliance" was one of
the few consumer level systems to use it. It had
a 16 megabyte SanDisk CF type chip soldered to the
board. On the chip was a compressed QNX operating
system and applications. At boot, a loader would
decompress the whole lot into system RAM.

The flash RAM chips used in Compact Flash and other
similar solid state memory devices like Memory Stick,
Smart Media, MMC, Secure Digital, and XD Picture Card
can only withstand a "limited" number of write cycles
before they begin to fail. The definition of "limited"
has been a moving target. The original full size
PCMCIA RAM cards (not the battery powered DRAM ones)
started out with about a 10,000 write cycle lifetime.
The latest technology has stretched the write cycle
life into the millions, but still nowhere near as
many as a hard drive.

=====
"When you are wrestling for possession of a sword, the man with the handle always wins." Hiro Protagonist

__________________________________
Do you Yahoo!?
Yahoo! SiteBuilder - Free, easy-to-use web site design software
http://sitebuilder.yahoo.com