Hi Justin Fontes,

Just review this thread from the first post:

Look at the first post in this thread by the OP.


What would be your answer?
Look at the number of posts in this thread talking about I2C and UART.

After all those many posts...if the OP now tells you that:
1. the 2 8051s are on the same board...what will be your answer? or
2. the distance between 8051s is 10mtrs or more, with noisy environment...what will be your answer? or
3. the speed of data transfer is >1Mhz...what will be your answer? or
4.....

How would you feel after about 30~40 posts in this thread the OP gives the above information.
Let us assume "the OP says it is Option 1 above."
Now how would the other members feel when they have posted for serial communication, SPI, Parallel... Wouldn't they feel, that their precious time would have been saved, if the OP had given this information in the first post?

There are "n" number of possible answers to the OPs question.
You cannot suggest the right solution unless you know some more details about the product.

(Well, I am NOT asking to divert the core design of the product), but you can atleast give this much information?
We never asked "what is your product", or "other product details", we have asked only the information related to the question; so that the OP gets to the solution fast. And, I don't think, anybody can copy the product just by answering the above questions !!!
OP asked only for "how to connect" she never diverted the information of what data is flowing between the 8051s, or what is the product?

In so many years, I do not remember a single incident when anybody has asked for product details other than that required to come to a solution for the OPs question.

Edit:
My argument is the OP must give some background information about the question, that will help to come to solution very quickly. It will save everybody's time and energy.