classes of instruction do they (intel 8051 microprocessor family) offer

You should really refer to the instruction set manual for the answer to that.

http://www.keil.com/dd/docs/datashts/intel/ism51.pdf

Once you start researching this, you'll find out that 8051 devices all offer the same exact instruction set. The only exceptions are...

* Chips that have 2K of code space may not support the LJMP/LCALL instructions.

* Chips that use the unused opcode (A5) for some special purpose.

* New extended devices like the Intel 251, Philips MX, and Dallas 390.

Jon