| Pin | Description | 
|---|---|
| 1 | Not used | 
| 2 | RXD (receive data) input to the printer | 
| 3 | TXD (transmit data) output from the printer | 
| 4 | DTR (data terminal ready) output from the printer -- controls when the host may send data | 
| 5 | Chassis ground | 
| 6 | DSR (data set ready) input to the printer | 
| 7 | RTS (request to send) output from the printer -- always in the ACTIVE condition when the printer is turned on | 
| 8 | CTS (clear to send) - Not used by the printer | 
| 9 | +5 V @ 0.75 A fused | 
| DB-25S Connector to DTE Device (PC) | DB-9P Connector to Printer | DB-9S Connector to DTE Device (PC) | DB-9P Connector to Printer | |||
| DB-25S Connector to DCE Device | DB-9P Connector to Printer | DB-9S Connector to DCE Device | DB-9P Connector to Printer | |||