Q: What's the difference between flash memory and SRAM?
A: SRAM is fast, expensive, requires battery back-up, doesn't take
much power to use.  Flash memory is cheaper per megabyte, available in
larger sizes, will hold data forever without power, very slow for
writing (on the order of the speed of a floppy disk), requires
significant power for writing, and will eventually wear out when
written to many times (though some flash cards have a lifetime
guarantee, and nobody has yet posted that their flash card wore out).

Both technologies have plenty of satisfied users.

Q: Will <Random PCMCIA Card> work in a 100/200LX?
A: Best answer: ask the vendor, and be sure you're allowed to return
it if it doesn't work.  Most vendors will know if their cards are
compatible with a machine as common as the 100/200LX.

Longer answer:  The 100/200LX PCMCIA slot is PCMCIA 2.0 compatible,
and able to accept type I or type II cards.  It supplies 5 or 12
volts.  It can only supply 150mA, so it has trouble with certain
cards which attempt to draw high current.  Most modems, SRAM cards,
and ATA (Sundisk-style) flash cards work fine.  Most ethernet
adapters and GPS receivers draw too much current to work. Intel-style
flash cards (like the Newton uses) are not supported, but see next
question.

Common confusion:  PCMCIA _Type_ is always listed in roman numerals,
and refers _only_ to the thickness of the card.  PCMCIA _Release_ is
listed in arabic numerals, and refers to the version of the interface
specification.

If a card draws too much current to work in the 100/200LX, using the
AC adapter won't help.

Q: How can I use a Newton flash card in a 100/200LX?
A: This is not for the squeamish.  HP does not support Intel-style
flash cards on the 100/200LX, so if you have any problems making it
work, you're pretty much out of luck.

However, some users have reported varying degrees of success with
them.  They require that you obtain MS-FLASH.SYS for normal use, and
MEMCARD.EXE is required to format the card. These files are NOT
public domain, and not available at any ftp site.  Some people have
reportedly pirated them from an Omnibook (probably illegal). If
anyone knows of an official way of obtaining up-to-date versions of
these files, please tell the editor.

At least one user has reported that there is some incompatibility
between the system manager (or at least the database apps) and
MS-FLASH.SYS, such that the flash card could only be used in raw DOS
mode outside of the system manager.  Other users have reported that
continually writing and moving files around on the card slowly
consumes small amounts of disk space, which can only be recovered by
backing the card up, reformatting, and restoring.

Note that this entire discussion is about Newton flash cards, not
Newton SRAM cards.  Several posters have been able to use Newton SRAM
cards without difficulty.

Q: How can I use a PCMCIA ethernet adapter?
A: Most ethernet adapters draw more power than the palmtop can
provide.  An exception is a card made by Silicom Connectivity
Solutions (800 474-5426 or 206 882-7995) which was designed with the
palmtops in mind.

The Socket Communications and Xircom ethernet adapters are reported
to come close to working, though there are problems getting the
supplied drivers to work on the 100/200LX.