A Java Ring is a finger ring that contains a small microprocessor with built-in capabilities for the user, a sort of smart card that is wearable on a finger. Sun Microsystems’s Java Ring was introduced at their Java One Conference in 1998 and, instead of a gemstone, contained an inexpensive microprocessor in a stainless steel iButton running a Java virtual machine and preloaded with applets (little application programs). The rings were built by Dallas Semiconductor. Workstations at the conference had “ring readers” installed on them that downloaded information about the user from the conference registration system.
This information was then used to enable a number of personalized services. For example, a robotic machine made coffee according to user preferences, which it downloaded when they snapped the ring into another “ring reader.” The Java Ring is an extremely secure Java-powered electronic token with a continuously running, unalterable real-time clock and rugged packaging, suitable for many applications. The jewel of the Java Ring is the Java iButton — a one million transistor, single chip trusted microcomputer with a powerful Java Virtual Machine (JVM) housed in a rugged and secure stainless-steel case.