In computer architecture, 4-bit integers, memory addresses, or other data units are those that are at most 4 bits wide. Also, 4-bit CPU and ALU architectures are those that are based on registers, address buses, or data buses of that size. The Intel 4004, the world's first commercially available single-chip microprocessor, was a 4-bit CPU. (The F14 CADC was created a year before the 4004, but its existence was classified until 1997.) Also, the HP48 Saturn processor (a commonly used scientific calculator) is basically a 4-bit machine, though it strings multiple words together, e.g. its 20-bit memory addressing.
The 1970s saw the emergence of 4-bit software applications for mass markets like pocket calculators.
With 4 bits, it is possible to create 16 different values. All of the hexadecimal numbers can be written with 4 bits.
| Binary |
Octal |
Decimal |
Hexadecimal |
| 0000 |
0 |
0 |
0 |
| 0001 |
1 |
1 |
1 |
| 0010 |
2 |
2 |
2 |
| 0011 |
3 |
3 |
3 |
| 0100 |
4 |
4 |
4 |
| 0101 |
5 |
5 |
5 |
| 0110 |
6 |
6 |
6 |
| 0111 |
7 |
7 |
7 |
| 1000 |
10 |
8 |
8 |
| 1001 |
11 |
9 |
9 |
| 1010 |
12 |
10 |
A |
| 1011 |
13 |
11 |
B |
| 1100 |
14 |
12 |
C |
| 1101 |
15 |
13 |
D |
| 1110 |
16 |
14 |
E |
| 1111 |
17 |
15 |
F |
List of 4-bit Processors
External references
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