Add-in Modules

Additional hardware/software functionality can either be built into the product or
added into an expansion slot. The choice here is to use a memory card slot (for
instance, the Sony Memory Stick) or a PC card. PC cards come in three thicknesses:
 Type 1 (3.5 mm)
 Type II (5mm)
 Type III (10.5 mm); incompatible with most PDAs (too thick)
PC cards can either have their own power supply or can be parasitic; that is, they can
take power from the host device. PC cards could host a hard disk or a wireless modem
or a GPS receiver or a Bluetooth transceiver. Power drain on the host device can be
significant.
Hardware does still provide a convenient mechanism for delivering software value.
The value of the wireless PC modem is as much in the GSM software protocol stack as
in the wireless RF IC. A plug-in CMOS imaging device with embedded MPEG-4
encoder/decoder and memory expansion for image and video storage is an example of
add-on plug-in hardware/software value. The combined GPS receiver and MPEG-4encoder/decoder from Sony goes into the Sony Memory Stick expansion port. The
CMOS imager is a 100,000-pixel device. These products are described by Sony as personal
entertainment organizers, or PEOs.