What is "RTFM The "'51 bible" chapter 2 download "?
ok, nice and slow:
To the left of this message there is a column with fields with pictures and words. One of those fields has a green globe, a purple globe and a blue globe and the word "links". Click there. That will bring up a list of things. One of those things is the "bible" ch2 programmers guide: '51 programmers guide and instruction set - (it is near the end). When you click on the blue part of that you will download chapter two (The programmers guide) of the basic '51 text. In that you will find the answer to all questions you have about the '51 instruction set.

Erik