How Removable Storage Works

By: Jeff Tyson

Solid-State: Cards

A SmartMedia card measures about twice the surface area of a quarter.

Flash-memory storage devices such as CompactFlash or SmartMedia cards are today's most common form of electronic nonvolatile memory. CompactFlash cards were developed by Sandisk in 1994, and they are different from SmartMedia cards in two important ways: They are thicker, and they utilize a controller chip.

CompactFlash consists of a small circuit board with Flash-memory chips and a dedicated controller chip, all encased in a rugged shell that is several times thicker than a SmartMedia card. The increased thickness of the card allows for greater storage capacity.


CompactFlash sizes range from 8 MB to an incredible 4 GB. The onboard controller can increase performance, particularly on devices that have slow processors. However, the case and controller chip add size, weight and complexity to the CompactFlash card when compared to the SmartMedia card.

The solid-state floppy-disk card (SSFDC), better known as SmartMedia, was originally developed by Toshiba. SmartMedia cards are available in capacities ranging from 2 MB to 128 MB. As seen below, the card itself is quite small.

SmartMedia cards are elegant in their simplicity. A plane electrode is connected to the Flash-memory chip using bonding wires. The Flash-memory chip, plane electrode and bonding wires are embedded in a resin using a technique called over-molded thin package (OMTP). This allows everything to be integrated into a single package without the need for soldering.

SmartMedia cards are capable of fast, reliable performance while allowing you to specify the data you wish to keep. They are small, lightweight and easy to use. They are less rugged than other forms of removable solid-state storage, so you should be very careful when handling and storing them. Check out How Flash Memory Works for more information.