DESKTOP x1k10                                ͻ
                                     BLITTER     
                                 bit assignments 
                                ͼ
                                 Atari BLock bIT TransfERrer processor
                                 (optional)
             Ŀ
              Control Register     b15=busy
                                       0:nothing
                                       1:busy
                                   b14=share the bus with MC68000
                                       0:yes , 64~ each
                                       1:no
                                   b13=source indicates next pattern line
                                       0:no
                                       1:yes
                                b11-b8=[b3-b0]=next pattern line
                                    b7=source read at begin of the line
                                       0:no
                                       1:yes
                                    b6=source read at end of the line
                                       0:yes
                                       1:no
                                 b3-b0=source shift in bits
             
           Ŀ
            Operation Register   b9-b8=source type
                                      0:1
                                      1:pattern
                                      2:source
                                      3:source and pattern
                                 b3-b0=logical operation
                                        0: d =   0
                                        1: d = s . d
                                        2: d = s . d
                                        3: d =   s
                                        4: d = s. d
                                        5: d =   d
                                        6: d = s  d
                                        7: d = s + d
                                        8: d =(s + d)   = s. d
                                        9: d =(s  d)
                                       10: d =   d
                                       11: d =(s. d)   = s + d
                                       12: d =   s
                                       13: d =(s . d)  = s+ d
                                       14: d =(s . d)   = s+ d
                                       15: d =   1
           
               Ŀ
                Source Address [b23-b0]=source address
               
          Ŀ
           Destination Address [b23-b0]=destination address
          
           Ŀ
            Horizontal Counter  b15-b0=destination horizontal counter
                                                          (in words , 0:65536)
           
             Ŀ
              Vertical Counter  b15-b0=destination vertical counter
                                                          (in lines , 0:65536)
             
  Ŀ
   Source Horizontal Increment  b15-b0=source horizontal signed increment
  
    Ŀ
     Source Vertical Increment  b15-b0=source vertical signed increment
    
   Ŀ
    Destination Hor. Increment  b15-b0=destination horizontal signed increment
   
  Ŀ
   Destination Vert. Increment  b15-b0=destination vertical signed increment
  
               Ŀ
                Beginning Mask  b15-b0=beginning mask
               
                  Ŀ
                   Middle Mask  b15-b0=middle mask
                  
                  Ŀ
                   Ending Mask  b15-b0=ending mask
                  
                 Ŀ
                  Pattern Line  b15-b0=pattern line
                 
