JAVACAM: trimming Java down to size

JavaCam is an embedded sensor device that connects to the Internet and operates with as little as 1.5 Mbytes of total system memory. To determine how small a Java system we could build that would still support a Java Virtual Machine, we wrote the Java Nanokernel, a very thin operating system. We then ported Sun's Java Development Kit 1.0.1 to JN. This port included the complete Java language and all of the core Java packages except java.awt. In this article, we begin by describing JN and the port of JDK 1.0.1 to it. We then describe our first significant application, JavaCam, a camera that is remotely programmable in Java and Internet accessible.