Kim Rowe at RoweBots Research let me know his company now offers Unison Version 5 and the open-source version of Unison Version 4. These two ultra-tiny embedded-Linux and POSIX-compatible real-time operating systems (RTOSs) let product developers who use--or want to use-- the Renesas SH-2A microcontroller (MCU) family work with Linux for the first time.

I have written about Unison, an open-standards-based RTOS, and think it will suit many applications, such as home-automation devices, security systems, vending machines, networked devices, and so on. According to Rowe, "Unison increases embedded development productivity and reliability for SH-2A developers by substantially reducing the difficulties of developing complex systems. OEM developers can create improved applications with reusable components supported by the Unison product... Modular, advanced networking protocols, file systems, a POSIX shell and other components are available."

Rowe continued, Unison's ultra-tiny footprint and open-standards compatibility give it the capability to support Linux-like development where Linux variants cannot run. This approach reduces risk and the cost of system hardware... OEMs benefit from simple migration of software between processor architectures without code changes or GPL concerns. Developers don't require retraining and can easily reuse application code.

Unison V4 and V5 run on x86 host PCs that use the Windows XP or Vista operating system. These versions of Unison are available now with commercial royalty-free RTOS licenses with serial support and a multimedia file system. The cost start at $US 999 per project. RoweBots also offers support, training, and consulting for the families of MCUs sold by Renesas.

For more information about RoweBots' Unison, support for non Renesas MCUs, and other software, visit: www.rowebots.com

If you have had experience with Unison or have taken another approach to Linux in MCUs, share your experiences here.

--Jon Titus