What is the difference between AT89C51 and AT89S51?

Question

How do you connect these to your computer? Which one would be easier to burn?

Answer 1

Some answers are there:

• In 89S51 what s means 89c51 what c means?
• Difference between 89c51 and 89s51?
• difference between 89c51 and 89s51

The main feature of S version is ISP, which stands for in system programming.

Answer 2

The information you seek can be found by comparing the data sheets: AT89C51, AT89S51, however you will see in this first link that it states:

Not recommended for new designs. Use AT89S51.

So that probably makes your last question irrelevant, you should use the AT89S51 regardless.

With regard to your second question (which I interpret as "connecting to a development host"), I suggest that you use an off-the-shelf development board unless you have the means and skill to produce your own. In-system programming can be achieved through the UART (there's an app. note in the link above), so you'll need a PC with an RS-232 serial interface and a NULL-Modem cable (the latter may come with the board). If you do not have a serial port on your PC, get a USB serial port adapter.

Obviously you need the development tools; at leas a compiler, and for debugging you'd benefit from an emulator; again the link above has references to tools.

Overall; read the manufacturer's documentation is the answer to all your questions! ;-)