02-02-2012, 02:37 PM
The 8051 Microcontroller and Embedded Systems
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INTRODUCTION TO COMPUTING
Numbering and coding systems
Digital primer
Inside the computer
Human beings use base 10 (decimal)
arithmetic
There are 10 distinct symbols, 0, 1, 2, …,
9
Computers use base 2 (binary) system
There are only 0 and 1
These two binary digits are commonly
referred to as bits
Adding the digits together from the least significant digits
. If the result is less than 16, write that digit
as the sum for that position
.If it is greater than 16, subtract 16 from it
to get the digit and carry 1 to the next
digit
The ASCII (pronounced “ask-E”) code assigns binary patterns for
Numbers 0 to 9
All the letters of English alphabet,
uppercase and lowercase
Many control codes and punctuation
marks
