# Figure 6-3: Methods for calculating the number of possible values in a given number of bits in Objective-C Draw PDF417 in Objective-C Figure 6-3: Methods for calculating the number of possible values in a given number of bits

Figure 6-3: Methods for calculating the number of possible values in a given number of bits
Barcode Maker In Objective-C
Using Barcode maker for iPhone Control to generate, create barcode image in iPhone applications.
PDF 417 Creator In Visual C#
Using Barcode generator for .NET framework Control to generate, create PDF 417 image in .NET framework applications.
Remember, unlike grade-school math, where they taught you that zero was nothing, in computers, it represents an individual state and is counted So from 0 through 6 is actually seven individual numbers, not six
PDF 417 Generator In Visual Studio .NET
Using Barcode maker for ASP.NET Control to generate, create PDF417 image in ASP.NET applications.
PDF417 Generator In Visual Studio .NET
Using Barcode printer for .NET Control to generate, create PDF 417 image in Visual Studio .NET applications.
This is because you count the number you start from So, with eight bits (which we will be working with most), there are actually 256 possible values, ranging from 0 through 255 By the way, the mathematical formula for this computation is 2n (2 to the power of n), where n is the number of bits in question Exercise 6-1: Binary-to-Decimal Conversions Convert the following binary numbers to decimal numbers Answers are provided in the sidebar on the next page Do not use a calculator (it will only defeat the purpose of this exercise) 1 2 3 4 5 10001101 011011 110 111100001010 1001001001
Draw PDF 417 In Visual Basic .NET
Using Barcode drawer for .NET Control to generate, create PDF 417 image in VS .NET applications.
UPC-A Creation In Objective-C
Using Barcode maker for iPhone Control to generate, create GS1 - 12 image in iPhone applications.
Answers to Exercise 6-1 1 2 3 4 5 141 27 6 3,850 585
Drawing UCC-128 In Objective-C
Using Barcode generation for iPhone Control to generate, create UCC.EAN - 128 image in iPhone applications.
EAN13 Generation In Objective-C
Using Barcode creator for iPhone Control to generate, create UPC - 13 image in iPhone applications.
The second shortcut is that when doing a binary conversion, always count the type of digits (0 or 1) you have the least of, and then subtract or add as necessary For instance, if you wanted to determine the value of 11110111, you could add 128 + 64 + 32 + 16 + 0 + 4 + 2 + 1, as we have been doing; but the easier way would be to count the place with the 0 in it (the eights place) and subtract that number from 255 (the value the number would be if all of the bits were a 1)
Generate USS Code 128 In Objective-C
Using Barcode maker for iPhone Control to generate, create Code 128 Code Set B image in iPhone applications.
Generate Bar Code In Objective-C
Using Barcode drawer for iPhone Control to generate, create bar code image in iPhone applications.
Now that you have an understanding of binary, let's take a look at the IP address structure
Drawing Bar Code In Objective-C
Using Barcode creation for iPhone Control to generate, create barcode image in iPhone applications.
Making Code 39 Full ASCII In Objective-C
Using Barcode generator for iPhone Control to generate, create Code 39 Full ASCII image in iPhone applications.
IP Structure
EAN-8 Supplement 2 Add-On Printer In Objective-C
Using Barcode creator for iPhone Control to generate, create EAN / UCC - 8 image in iPhone applications.
Barcode Recognizer In Java
Using Barcode scanner for Java Control to read, scan read, scan image in Java applications.
As mentioned previously, IP addresses are composed of two primary units: the network portion and the host portion
ANSI/AIM Code 128 Printer In None
Using Barcode generator for Word Control to generate, create Code 128C image in Word applications.
ANSI/AIM Code 128 Creator In Java
Using Barcode drawer for Java Control to generate, create Code 128 Code Set B image in Java applications.
In addition, every IP connection requires at least one unique IP address However, two additional pieces are commonly required to achieve IP connectivity: a subnet mask and a default gateway The subnet mask is required in all IP implementations It defines which part of the address is the host and which part is the network by using a Boolean process known as ANDing ANDing is very simple in binary It is basically multiplication For example, Figure 6-4 shows an IP address and a subnet mask To arrive at the network address (the portion that defines which network you are on), you simply multiply the IP address (in binary) by the subnet mask (in binary) The result is a binary number that you can convert back to decimal to learn the network address This is where routing comes into play Routing is the act of forwarding a packet from one logical network or subnetwork to another A router is simply the device that performs this process
Generating Barcode In .NET
Using Barcode printer for Visual Studio .NET Control to generate, create bar code image in .NET framework applications.
Bar Code Creation In None
Using Barcode creator for Font Control to generate, create barcode image in Font applications.
Figure 6-4: Basic ANDing When a host wants to communicate with another host, it takes that host's IP address and its own IP address, and performs the ANDing process with both addresses If the result for both addresses is the same, the host is assumed to be on the same logical network as the other host, and it should be able to communicate directly If the result is different, the hosts are assumed to be on different logical networks (that is, separated by a router), and they must use a router to reach each other (Figure 6-5 shows an example)