CPU is programmable.
CPU is a hardware which is controlled by easy-to-modify software.
| Instruction | Description |
|---|---|
| SUB (Subtract) | Subtract two registers, store value into second registers. |
| JUMP | Update instruction address register to new address. |
| JUMP_NEG (Jump Negative) | If ALU result was negative, update instruction address register to new address. |
| HALT | Program done. Halt computer. |
JUMP_IF_EQUAL, JUMP_IF_GREATER, ...