8051 and 8052 aren't interchangable, but they are similar.

The 8052 is identical to the 8051 with the following enhancements:

1. The 8052 has 256 bytes of internal RAM, the 8051 has 128.

2. The 8052 has three (3) 16-bit timers, the 8051 has two (2). The third timer has some new operation modes not available with the 8051.

... anyone else have others? Off the top of my head those are the two main differences.

Good luck,
Craig Steiner