Staking out its position to bring embedded Java technologies to market, Integrated Systems Inc. (ISI) is aiming for an October debut of an interface between its pSOS operating system and Hewlett-Packard Co.'s embedded Java Virtual Machine.

HP's virtual technology caused a stir this spring, when it first appeared on the scene. In March, while the RTOS community was waiting for Sun Microsystems Inc. to unveil its EmbeddedJava specification, HP stunned the industry by announcing its own, homegrown Java implementation.

HP garnered lots of early support. Microsoft quickly weighed in with the news that it would license HP's new Java Virtual Machine and use it to integrate support for Java into the Windows CE operating system.

In May, four RTOS vendors took out HP licenses. Along with ISI, they are Lynx Real-Time Systems Inc., Microware Systems Corp. and QNX Software Systems Ltd. In addition, Wind River Systems Inc. (Alameda, Calif.) has endorsed — though it has not licensed — HP's technology.

From Sun's perspective, HP's implementation constitutes competition for its own EmbeddedJava, which has been licensed by nine RTOS vendors, including Microware, QNX and Wind River. (ISI does not hold an EmbeddedJava license, though it does have access to Sun's full implementation through its links with an Israeli company called NSI Comm.)

To avoid potential legal problems, engineers in HP's Embedded Software Lab constructed their embedded virtual machine as a clean-room implementation that complies with the Java VM specification. HP's 1.0 release includes a core set of standard binary libraries for the java.lang, java.net, java.util and java.io application-programming interfaces. HP's VM is designed specifically for the memory-constrained environments of embedded devices, with a ROM footprint of 500 kbytes and a RAM footprint of approximately 175 kbytes. Incremental garbage collection and multithreading are also featured. The VM currently runs on MIPS, Motorola, Intel X86 and StrongARM processors.

However, HP's technology isn't the only Java oar ISI has in the water. Besides gaining access to Sun's Java technology through NSI Comm, ISI has also licensed the Perc real-time Java clone from NewMonics Inc. (Ames, Iowa). Perc, which stands for "portable executive for reliable control," executes standard Java byte codes along with some proprietary real-time extensions and requires a footprint of only 512 kbytes.

ISI is pursuing this three-pronged approach in a bid to keep its options open and to serve the needs of different customers.

"HP and Perc are very similar. We'll be focusing Perc where people want to have access to all of the software. When someone wants the source code, we'll provide them that," Addiego said. "With HP, that will be the system we offer as an option with the pSOS environment. If somebody wants a full Java implementation, that's when we'll use NSI Comm."

Addiego said that HP engineers and ISI personnel will work together in the effort to develop the interface between ISI's pSOS operating system and HP's embedded VM. The technology will be offered to pSOS customers as an option, for an extra fee. The target platforms for the VM will be the same ones pSOS runs on, including PowerPC, ARM, MIPS and X86.

Trio of solutions
As to where such burgeoning Java technologies will find applications, ISI sees its customer base focused on communications and networking. "What people have been asking for is to be able to do functions like network management — the software pieces of it," said Addiego. "Our market typically requires very deterministic, very hard real-time systems oriented for custom boards."

ISI sees custom-board apps in areas ranging from communications and consumer electronics to office automation. A key selling point for the company is its ability to offer networking capabilities such as SNMP support and other enabling technologies. "We're really focused on that right now," Addiego said. "Our whole campaign is focused on network-enable devices."

More and more, embedded developers may find that Java's larger memory requirements make it suitable for user-interface tasks. "The places that are going to use Java are the larger areas: the larger switches, the larger concentrators, which have a management board in there along with 15 other boards that are doing the hard real time," said Addiego. "That management board is going to be the one they want to use Java on."