What does "8-bit" or "16-bit" etc. mean?

Question

The NES is an 8-bit machine, the SNES is 16-bit, the Genesis is 16-bit...

What does all of this mean??

A detailed explanation would be good.

Answer 1

eh, the most detail i can give you is probly that the more bit, the more space, memory, and power something has in the same amount of space...

bitrate means the speed that which it can power...so that goes along with it.

Answer 2

This gets rather technical.

A procesor has a bunch of tiny segments of memory called registers. These are much different in function than the cache which has become more famous and is purely for data storage. The registers are used in every computational operation. The number of registers varies depending on the chip, but functionally 3 registers is the absolute minimum.

Example:

Say you want to add two numbers together. We'll go with 3+1. In a high-level language, it looks just like how you would think it in algebra: <variable> = 3+1. But when you get down to amchine language, it's much more complicated. First you have to put a "3" into Register B. Then you have to put a 1 into Register C. Then you have to put in the binary code for addition into Register A. Tehen you have to send the signal to execute the operation (which will add 3 and 1, and overwrite Register B with the result).

The size of the register determines how large of a number the system can work with (natively; it's possible to work around this, but the efficiency of your program will suffer). It also determines how many different colors the system can display at a single time. And perhaps most importantly, it determines how many different operations the processer can actually have. For an 8-bit system, the number for all of these os 256 (the span of numbers can be 0 to 255 or -128 to 127, only 256 colors can exist in a color pallette, and there can only be 256 different operations). When you go to 16-bit, the numbers just to 65,536. 32-bit is over 4 billion.

The operations number is probably the most significant for power back then, as that meant that some operations that were common had to be handled with multiple seperate operations, simply because it wasn't quite as vital as 256 other operations were. Doing multiple operations is slower, and with the chip speeds what they were back then, that was significant.

Nowadays, bit counts aren't an accurate measure of computational power at all. XBox > Gamecube >>> PS2, but the XBox was a 32-bit system, the Gamecube was a 32-bit CPU with a 64-bit GPU, and the PS2 was a 128-bit system.

Answer 3

Let's just say:the more bits, the better

Answer 4

It refers to the width of the CPU's internal registers. 8 bits is one byte, and two bytes is one 16-bit word. Note that the Pentium class   processors have internal registers capable of processing "doublewords", which are 32 bits wide.

A byte is an 8-bit binary number. For example binary 105 is 1101001.