Published August 2001

FINE TUNING AN EMBEDDED IDEA

Part 2: Ethernet-Equipped RabbitCore Modules
by Fred Eady

Start • The Networking Core • Code Names and Comedy • Where and Why • Completing Initialization • Down to Business • Now What? • Sources and PDF

Last month, Greg Lake of Emerson, Lake, and Palmer was here visiting the Florida room and, while tutoring me on bass guitar, he suggested that the first subject in this series of Z-World and Rabbit Semiconductor articles should center on the new Z-World BL2000.

On the way back from dropping Greg off at the airport, my mind wandered back to a time before computers roamed the earth in great numbers. Those were the days of Osbourne, Tandy, Altair 8800, and the Southwest Technical Products Corp. 6800. The SWTPC 6800 had a whopping 32K of RAM and ran at a blistering 980 kHz. All this came in a rather large (but elegant) enclosure. The smallest RabbitCore module sports 128K of RAM, 256K of flash memory, and runs at 22.1 MHz. It’s a bit larger than an Elvis commemorative postage stamp.

A computer is a computer. No matter how big or how fast, the job is always the same—to move and manipulate electronic or mechanical bits that represent data to the user. I’m sure the IMSAI 8080 hooked to a mechanical TeleType was the cat’s meow back in 1976. In fact, I knew a NASA guy back then who used the IMSAI 8080 and TeleType to track stock market trends. He even made plots on the TeleType. What differentiates today’s computing devices from that now ancient IMSAI? In a word, networking.

The government, the military, and some universities were way ahead of the curve back then. Ethernet and the beginnings of what we now know as the Internet were sprouting in the fertile soil of the Xerox Alto workstation and ARPA project. Microsoft and Apple later tasted the fruit of the Xerox vines and we all prospered from the ARPA Net. I did some checking and Ethernet was not an option for any of the dinosaur computers I mentioned earlier. Serial communications was the big thing and the Internet was something college professors used for research and the military used to transfer "intelligence."

In this offering, I’m going to use the Rabbit Semiconductor RCM2100 Development Kit to give you some insight into using the networking facilities of the new Ethernet-equipped RabbitCore modules. I’m not going to concentrate on the hardware, as we already know its capabilities. Instead, I’m going to approach this from the software and standards point of view. As you’ll see, the hardware will speak for itself. It’s already talking in Photo 1.

Photo 1—The LEDs aren’t stock. I had some personal problems while adding the extra LEDs that come with the RCM2100 Development Kit. So, I had to replace them all so the picture would be pretty. The Sipex RS-232 IC, caps, and header pins also come as component parts of the RCM2100 Development Kit.

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