| Latched at S1 | Latched at S2 | Stretched |
| Read Lines - R(24) | Initialize (Z) | Strobe 1 (S1) |
| Write Lines - W(24) | Clear (C) | Strobe 2 (S2) |
| Function Code - F(5) | Busy (B) | |
| Subaddress - A(4) | LAM (L) | |
| Station No. - N | ||
| Q Response - Q | (Stretching to 200 msec provides visual indication.) | |
| X Response - X | ||
| P1 Bus | ||
| P2 Bus |