Series of Harvard architecture RISC
microcontrollers from Microchip
. Looking like innocent TTL logic
chips, they get tiny-to-huge interface/control jobs done with flair, speed, and low power consumption. They are the CPU
for the nifty Basic Stamp
s--running a powerful token
interpreter in under 1024 bytes.
The 16F84 is a very popular part: configured with FLASH RAM and programmable with free software / (very) minimal HW. Once code is stable, OTP chips bring the cost to nothing.
Inexpensive Compilers/emulators/programmers (see GNUpic) abound. If you do Windows, get the excellent MPLAB for all your editing and simulating needs. Free CD with datasheets and software for the asking from Microchip.