Stamp workings newbie

Archiver

I am a new to the basic stamp and am having alot of fun.

I would like to know is if anyone has a detailed explination of
how the serial communications downloads the data from the PC and how
the transitors and resistors effect the same. IE(if the X pin pulls
low the Q3 transistor does Y)

I am using this to learn about the actual electronics and how the
data transfer works and how the system stores data and transfer
information from the PIC to RAM.

Thanks for any input.

RFK