Take a look at today's offering in 805x-core microcontrollers.

SiLabs makes some parts, limited in some ways, but certainly not in code space or performance, and Maxim/Dallas makes some fast parts, that execute one instruction cycle in one clock tick, that aren't too slow either, and they plug in where that old i8751 you mentioned, but can't buy any longer, used to fit. They even take your old crystal oscillator and multiply it up so you can still use the old crystal if you want, yet still run at, essentially, 48x the speed. There are bunches of other mfg's whose products may save you a bunch of hassle, but you have to determine first what your requirements are. Silabs, Maxim, and a number of others have a 64KB (in some cases, even more) code-space FLASH memory on board, that you can program via your PC serial port.

Find out what's out there. You won't be disappointed.

One word of caution ... Search the 8052.com site for information BEFORE you buy into one or another of these parts, and be sure to read and digest the datasheets and user guides, before making a final decision. Too many users are bitten by the, "Oh, by the way ..." that's in the errata.

RE