| Code | Description |
|---|---|
| HLT | Halt the computer. Stops the clock. |
| MI | Memory address register in |
| RI | RAM in |
| RO | RAM out |
| II | Instruction register in |
| IO | Instruction register out |
| AI | A register in |
| AO | A register out |
| BI | B register in |
| BO | B register out (not connected) |
| S- (SU) | ALU subtract mode |
| SO (EO) | ALU sum register out |
| OI | Output display register in |
| O- | Output display signed mode (not connected) |
| CE | Program counter enable. Increment on clock pulse. |
| CO | Program counter out |
| CJ (J) | Program counter jump (program counter in) |
| FI | Flags register in |
Code in parentheses is what Ben uses in the videos.