faq entry one

An 8051/8052 microcontroller, generally speaking, is any microcontroller that has an instruction set compatible with the MCS-51 standard. Intel made the original 8051 microcontroller back in 1980 and its enhanced version 8052 (with doubled RAM and ROM) in 1983. Since then, dozens of semiconductor firms have chosen the MCS-51 standard for their lines of microcontrollers. When we speak of "8052" we are not just speaking of the Intel 8052, but also any other microcontroller that is compatible with the 8052 (it's faster then writing 8052-compatible every time we make reference to it), sometimes referring to them as '51 clones.

The marking used by other companies usually contains the "51" or "52" digit-pair, but generally, there are no defined rules for the marking. However, sometimes, the following common points can be found in the marking (don't take these for rules, just as a clue):

8051 inside
SW model
How to program (languages)
About device programming ("burning")
peripherals and communication lines/buses
51 in FPGA - softcores
a few typical applications and projects
development (debugging) tools - simulators, emulators, monitors, some debugging ideas
books, links?