@Crusty1: Yes, and that little Atmel MCU provides more power than some of those 'high-performance' microcomputers from early 80's.
I still have one CPU board and several expansion memory boards from one Gemini Multiboard Microsystem. It has 64KB of DRAM, 8K of EEPROM and one main Z80 (one extra Z80 was in charge of video generation). At boot time the EEPROM content was copied to SDRAM (reads routed to EEPROM, writes routed to SDRAM) and then the EEPROM was deactivated and program continued running from SDRAM. We used that board for data acquisition/processing and also for signals generation. The memory expansion boards used some similar switching thechnique and allowed to have up to 256KB of memory (a lot by that time!).
With one PIC microcontroller (3800 bytes of RAM, 64Kflash) we implemented the PLC for controlling the I/O and the CNC (including two axis curved paths routing) in one machine, inlcuding also serial and ethernet (via UDP) communications. We took it to the limit and of course, enjoyed making it, some people even came to say we would not be able to do it, but we did.
I think it's a matter of 'dimensioning', Atmel's AVR MCUs are very efficient for doing the job they have been designed for, and that's at the root in Arduino's success story.
@Victor: Oh so many years ago (about 35 years) when Max was just about out of short trousers. The UK home hobby electronics industry started the build your own computer craze off with the UK101 which was an English copy of the Ohio Scientific 600 single board computer, with a fledgling Microsoft operating system in ROM.
I think it was this that made me a nut for small is beautiful, at the time 3 K bytes of memory cost me £300 almost two months wages.
When you get as hard pressed as that, then using every resource possible to squeze code into the available memory was the only way forward. I think this keeps me routed into the small systems now, as I can still be a one man band and do it all myself.
The Atmel chip at the heart of Arduino is suprisingly efficient, as many instructions only take one cycle so the 16 Mhz is essentially quite fast and the chip is very resilliant to bad handling.
I am just progressing to the Sam3 Arduino Due and will be interested to see what the speed difference is like for the same bit of code.
From my early times as a hardware developer, back in the 80's/90's, I was always very lucky to have MCU boards all around for my daily work and research tasks, with many different processors like the Z80, 68HC11, 8085, 80286, TMS320C10/C30 and currently PICs, Altera NIOS-II, several ARM7TDMI, Cortex M3/M4 from ST/NXP/Freescale, iMX26, and even some more peculiar ones. I always had very powerfull boards (in MHz/MIPS/DSP/etc) to play with, some designed by our own team and some from others.
I always needed 'power' for the applications I was working on and that perhaps conditioned my mind to even make me some times wonder, why is so popular a board with such a limited power, just a few KB of RAM and not too much EEPROM/FLASH? Only the price? definitely not.
In my personal case, what attracts me from the Arduino boards and will make me someday acquire one is more the community achievements than the board itself. There're really brilliant people out there making surprising things with those tiny little things called Arduino boards.
The RasPi called my attention some time ago, but at the end I decided to give it a try to the Beaglebone Black.
This is a very good merging point to two very much matured and accepted platforms for enthusiasts Raspberry Pi and Arduno. Many new developments will be in the pipeline after this. May be it will give rise to a new community one may call "Raspduno"!!!.
@Max: Looking back over some of your comments about getting to grips with Arduino I ended up downloading the Arduino Workshop e-book from Amazon. This is an absolute gem of a book. It may even get me to like using C as a language for AVR.