list of some of the most common registers used in a basic computer
| Register | Symbol | Number of bits | Function |
|---|---|---|---|
| Data register | DR | 16 | Holds memory operand |
| Address register | AR | 12 | Holds address for the memory |
| Accumulator | AC | 16 | Processor register |
| Instruction register | IR | 16 | Holds instruction code |
| Program counter | PC | 12 | Holds address of the instruction |
| Temporary register | TR | 16 | Holds temporary data |
| Input register | INPR | 8 | Carries input character |
| Output register | OUTR | 8 | Carries output character |
The Memory unit has a capacity of 4096 words, and each word contains 16 bits.
- Data Register (DR) contains 16 bits which hold the operand read from the memory location.
- Memory Address Register (MAR) contains 12 bits which hold the address for the memory location.
- Program Counter (PC) also contains 12 bits which hold the address of the next instruction to be read from memory after the current instruction is executed.
- Accumulator (AC) register is a general purpose processing register.
- Instruction register (IR) is placed in the Instruction read from memory.
- Temporary Register (TR) is used for holding the temporary data during the processing.
- Input Registers (IR) holds the input characters given by the user.
- Output Registers (OR) holds the output after processing the input data.