Comptia A+ Exam Help

[aeonsky]

Hello everyone!

 

I'm currently studying for the CompTia A+ certification. Right now I'm reading the A+ Complete Study Guide, and in one of the sections "VGA Graphics", it comes up with this:

 

...for every power of 2 that the number of simultaneously displayed colored increases, you need another on the connector to transmit them. Four pins for 16 colors is not a big deal, but 32 pins for over 4 billion become a bit unwieldy.

 

And I'm just a tad confused about that. Here is the table for pins vs colors...

 

P  |  C

-------

1  |  1

2  |  2

3  |  4

4  |  16

5  |  256

6  |  65,536

7  |  4,294,967,296

 

As you see, 7 pins reach the 4 billion mark. So I'm not sure how they got 32 pins get a tad over 4 billion colors.

 

If my table/thinking is wrong, please do correct me. Thanks for the help.

 

 

[.josh]

you're doing the math wrong.  With powers of 2, it's 2 multiplied by itself a certain number of times.  So for instance, a 4 pin connector would have 2 * 2 * 2 * 2 = 16 colors.

 

1 : 2

2 : 4

3 : 8

4 : 16

5 : 32

6 : 64

7 : 128

8 : 256

9 : 512

10 : 1024

11 : 2048

12 : 4096

13 : 8192

14 : 16384

15 : 32768

16 : 65536

17 : 131072

18 : 262144

19 : 524288

20 : 1048576

21 : 2097152

22 : 4194304

23 : 8388608

24 : 16777216

25 : 33554432

26 : 67108864

27 : 134217728

28 : 268435456

29 : 536870912

30 : 1073741824

31 : 2147483648

32 : 4294967296

[aeonsky]

Ooooh, read it wrong.

 

It is 2^(# of pins) = (# of colors)

 

Thank you!

[corbin]

Or, number of pins = log2(colors).

 

 

;p