You never know what’s going to show up in your inbox. A recent note from Matt Miller, tooling engineering manager for Commercial Forged Products, spurred a look back.
“I have been marveling at the proliferation of incredibly powerful and precise modules of incredible varieties that are available these days. The price is comparatively cheap and, whoa, the bang for the buck is big,” he wrote.
“I’d be very interested to see someone do an objective comparison of some or even one piece of equipment that is available for the hack like me (mechanical engineer who dabbles with electronics) at a reasonable price versus what was available 10 years ago,” he noted.
“Every time I thumb through Electronic Design, I’m amazed at the range of products that are available now that are almost commodities (maybe they are for all I know) today that were seriously cutting-edge just years ago,” he added.
We exchanged a few e-mails, and I took a look to see what was sitting around the lab. I decided to go a bit further back to 1976 to see what developers and hobbyists had available then.
A LOOK THEN... One of the oldest single-chip microcontrollers is the Intel 8748 (Fig. 1). It is an EEPROM version in the MCS-48 line that eventually led to the 8051, whose architecture is still found in mainstream micros. I happen to still have a couple of 8748s in a drawer. They go back to my times at the RCA Sarnoff Research Center in Princeton, N.J., when Intel was also rolling out the 8088 that started the PC revolution.I don’t remember what the quantity price was, but they weren’t cheap compared to today’s small micros, which cost less than four bits, or 50 cents. Still, we marvelled at the designs we could come up with and how small they were then.
There were choices back then but not the plethora of options available today. Then, the massive choices were in discretes and dual-inline packages (DIPs) from adders to multiplexers. Clock rates were above a megahertz, though most instructions required multiple clocks.
AND A LOOK NOW... Spin ahead to 2006 and we have the Parallax Propeller (Fig. 2). This eight-core, 32-bit chip consumes the same 100 mW assuming all cogs (cores) are in play. Comparisons are hard between such disparate architectures, but it’s safe to say that the Propeller is faster by well over a factor of 100.In one way, the Propeller is similar to the MCS-48 family. Both provided basic parallel interfaces. Serial ports were implemented in software. Of course, the Propeller can run a serial line quite a bit faster, including the ability to drive a VGA display. Also, each core has significantly more power and resources than an MCS-48 chip. Plus, the Propeller is easier to program.
The choices vary widely these days, making a designer’s selection more interesting. At the other end of the spectrum lies a host of tiny six-pin micros that cost less than 50 cents and sip nanowatts in sleep mode. Skip again to the 32-bit end with a single-core, Stellaris 32-bit ARM Cortex-M3 from Texas Instruments for under a dollar (see “32-Bit ARM MCU Hits One-Dollar Mark” at www.electronicdesign.com, ED Online 12358).
The venerable Intel 8748H is still available for $12.95 at Jameco Electronics, or you can check eBay. By the way, the Propeller is also available in a 40-pin DIP and costs around $5.