USE CURSOR KEYS TO SCROLL TEXT.    
      USE CURSOR KEYS TO SCROLL TEXT.    
                                         
         Parallel Data Transfer V2       
                                         
  If you can get the User Port to behave 
  as if it were a printer then you have  
  a simpler way of transporting data from
  any computer with a printer port to the
  beeb, i.e no baud rate etc. to worry   
  about. This adaptor does just this, the
  program then saves the incoming data to
  a previously opened file when the tran-
  sfer is complete pressing ESCAPE closes
  the file.                              
                                         
  The printer side of this adaptor can   
  either have a centronics socket into   
  which the normal printer lead may be   
  plugged or you could connect direct to 
  the source computer.                   
                                         
                                         
  Adapter diagram                        
  ---------------                        
                                         
                                         
    N/C                                  
           O X O O O O O O O             
    N/C                                  
           O X O O O O O O O             
    BUSY                                 
           O X O O O O O O O             
    ACK                                  
           O X O O O O O O O             
  bit 7                |,,,,,,, bit 7    
           O X O O j O O X O ,,,,,,,,    
  bit 6            j   |,,,,,,, bit 6    
           O X O O j O O X O ,,,,,,,, 0v 
  bit 5            j   |,,,,,,, bit 5    
           O X O O j O O X O ,,,,,,,, 0v 
  bit 4            j   |,,,,,,, bit 4    
           O X O O j O O X O ,,,,,,,, 0v 
  bit 3 ,,,,,,,|   j   |,,,,,,, bit 3    
  ,,,,,,,, O X O O j O O X O ,,,,,,,, 0v 
  bit 2 ,,,,,,,|   j   |,,,,,,, bit 2    
  ,,,,,,,, O X O O j O O X O ,,,,,,,, 0v 
  bit 1 ,,,,,,,|   j   |,,,,,,, bit 1    
  ,,,,,,,, O X O O j O O X O ,,,,,,,, 0v 
  bit 0 ,,,,,,,|   j   |,,,,,,, bit 0    
  ,,,,,,,, O X O O   O O X O ,,,,,,,, 0v 
 STROBE ,,,,,,,|       |,,,,,,, CB2      
  ,,,,,,,, O X O O X O O X O ,,,,,,,, 5v 
                       |,,,,,,, CB1      
           O O O O O O O X O ,,,,,,,, 5v 
                                         
                                         
 Centronics                  User Port   
 Side                        Side        
                                         
  Track direction is across the screen.  
                                         
  N/C not connected                      
                                         
  X indicates cut track.                 
                                         
  Both grounds need to be connected      
  together to provide a common reference 
                                         
  Function                               
  --------                               
          When the BUSY signal is low    
  8 bit data comes in the centronics     
  side, then the strobe pulse is sent    
  which causes a CB1 interrupt, raising  
  the BUSY signal. After dealing with    
  the data, BUSY is again set low.       
                                         
  Signals                                
  -------                                
                                         
  STROBE.is sent by the computer when the
         data is valid.                  
                                         
                                         
  ACK..is an output of the printer which 
       tells the computer it has received
       the last character sent and is    
       active low.                       
                                         
  BUSY.is an output of the printer which 
       when high tells the computer not  
       to send any more data.            
                                         
                                         
    DATA                              IN 
                                         
    STROBE                            IN 
                                         
    ACK/BUSY                          OUT
                                         
                                         
  The program                            
  -----------                            
  There are two modes of operation :-    
                                         
  Binary mode                            
            All data is passed and saved.
  Check for characters ignored, not sent 
  to the printer by the transmitting     
  computer.                              
                                         
  Ascii mode                             
            Character 10's (line feed)   
  are not saved, this tidies documents   
  from various machines as there is no   
  standard set order of the line feed    
  and carriage return that may mark the  
  end of each line.                      
    Also there is a routine to ignore    
  standard printer commands and some     
  Epson commands, these can be tailored  
  to individual needs.                   
    In this mode text is written to the  
  screen (80 columns) so you can see what
  is being saved, this has the bonus of  
  method of seeing a document before     
  being printed saving valuable paper.   
                                         
     PRESS SPACE FOR THE MAIN MENU.      
     PRESS SPACE FOR THE MAIN MENU.