| Pin | Symbol | Type | Function |
| 1 | IR | Analog | Input current, bias voltage approximately GND |
| 2 | 12 | Analog | Input current, bias voltage approximately GND |
| 3 | GND | Supply | Ground |
| 4 | RF | Analog | External resistor to GND sets oscillator frequency |
| 5 | 13 | Analog | Input current, bias voltage approximately GND |
| 6 | NER | Digital | Digital control of read channel (low active) |
| 7 | NE2 | Digital | Digital control of channel 2 (low active) |
| 8 | NE3 | Digital | Digital control of channel 3 (low active) |
| 9 | VCC2 | Supply | +5 V power supply for IOUT |
| 10 | ENOSC | Digital | Enables RF oscillator (high active) |
| 1 1 | ENABLE | Digital | Enables output current (high active) |
| 12 | RS | Analog | External resistor to GND sets oscillator swing |
| 13 | GND | Supply | Ground |
| 14 | IOUT | Analog | Output current source for laser diode |
| 15 | VCC2 | Supply | +5 V power supply for IOUT |
| 16 | VCC1 | Supply | +5 V power supply for circuit |
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In real-time instruction trace, four status lines provide information on processor activity in real time (PST pins). A four-bit wide debug data bus (DDATA) displays operand data and change-of-flow addresses, which helps track the machine's dynamic execution path.