Pin No  Pin No     Signal                   Direction    Description                                      
        return                                                                                             
                                                                                                          

1       19         * Data Strobe            Input        Printer reads data line when this line is low.   
                                                         pulse width =>1 microsecond                     
                                                                                                          

2 - 9   20 -27     Data 1 - 8               Input        * Data lines, data 8 (pin 9 ) is MSB             
                                                                                                          

10      28         * Acknowledge            Output       pulse indicates printer has received data        
                                                                                                          

11      29         Busy                     Output       Data cannot be received when this line is high   
                                                                                                          

12      30         Paper Empty              Output       Goes high when out of paper                      
                                                                                                          

13                 Select                   Output       Goes high when printer is online                 
                                                                                                          

14                 Auto Feed XT             Input        Not Used                                         
                                                                                                          

15                                                       No connection                                    
                                                                                                          

16                 Signal Ground                         Logic ground level                               
                                                                                                          

17                 Frame Ground                          printer chassis                                  
                                                                                                          

18                                                       No connection                                    
                                                                                                          

9 - 30             Signal Ground                         Twisted pair return lines                        
                                                                                                          

31                 * Input Prime            Input        Print is reset  & goes online if signal low   
                                                         > 50 microseconds                               
                                                                                                          

32                 * Fault                  Output       Goes low when printer is Offline,out of paper, or 
                                                         error detected                                    
                                                                                                          

33                 Signal Ground                         Logic grond                                      
                                                                                                          

34                                                       No connection                                    
                                                                                                          

35                 +5Vr                     Output       Pulled up to +5volts thru a 3.3k ohm resistor    
                                                                                                          

36                 * Select In              Input        Not Used                                         
                                                                                                          

* indicates a low true signal