In computer terms what is a nibble?

Answer 1

In computer terms a nibble = 4 bits = 1/2 byte.

You can further define the data segment as:

Crumb = 2 bits

Nibble = 4 bits

Byte = 8 bits

Word = 16 bits

Double Word=32 bits

Jury still out on 64 bits and Sentence

In keeping with the spelling of "byte", the lick and nibble are sometimes spelled "lyck" and "nybble"

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A nibble is half a byte, but believe it or not, a byte does not necessarily have to have eight bits. I don't know of any computer platform that uses anything but 8 bit bytes these days, but in computer science terms, a byte is generally the smallest addressable element, and the size needed to store a character. You also might be surprised to know that not all machines use ASCII (eight bit bytes) characters. IBM Mainframes still use EBCDIC under their traditional operating systems, and that stands for Extended Binary Coded Decimal Interchange code, which accounted for the lion's share of data until a few decades ago. It's an extended version of BCD, which uses 4 bits to express numbers, and there's no technical reason that a BCD based machine couldn't have 4 bit bytes.

It's unlikely that you will ever encounter a computer that doesn't use eight bit bytes, but you may encounter people who studied computer science back in the 1970s.

Back in the "old" days (the 1960's) when computer's didn't have operating systems or hign level programming languages, you always dealt with the byte. On some machines the byte was 8 bits and on others it was 8 bits + a parity bit for 9 bits. There was "even" parity and "odd parity", meaning you set the parity bit on if an even number of bits = 1 in the original 8 bits, or set it on for an odd number of bits = 1 in the original 8 bits. The "word" was originally set to be the size of a register (everything was done through a set of registers). The registers were used to assemble the current instruction that you wanted the computer to execute (what kind of action, like move a byte, add, subtract etc., plus the final length of your data, which determined how many cycles the computer had to go through to execute your instruction, plus where the data was coming from and going to). The "word" length was pegged to the length of the register, meaning that in treating the computer like a book, each register was a word. Since the first computers were totally byte oriented, a word was 8 bits. When 16-bit registers were implemented, they became 16 bits, then 32 bits and now 64 bits. There are some computers today that even have 128 bit words. So a "word" is the length of the registers in whatever computer you are using. It is also the biggest chunk of bits that the computer can process at one time.

The word "nibble" was invented to specify the high-order 4 bits in a byte or the low-order 4 bits in a byte (like eating a nibble from a cookie, instead of the whole cookie). Since a number can be specified in 4 bits, you only needed a "nibble" to store a number. So, if you had a field that was all numbers, you could write it out in "nibbles", using half the space you would have used if it was in bytes. Back in those days, space counted. The first "mainframe" computers had 4k of memory (no, that really is 4k), so you didn't have any space to waste if you were doing something like payroll or inventory management.

In some cases, individual bits within bytes are used to store flags (yes or no for a given attribute) and, in at least one IBM manual, these were referred to as tidbits. IBM was not known for a sense of humor, but the term never became a generally accepted abbreviation.

Answer 2

a nibble is E3 short bits