40-Pin DIP socket | 68-Pin PLCC adapter socket
                  |                   
            1     |     26(I/O),44(I/O)
            2     |     25(In),45(I/O)
            3     |     24(In),46(I/O)
            4     |     23(In),47(I/O)              
            5     |     20(In),49(I/O)               
            6     |     11(I/O),59(I/O)
            7     |     10(I/O),60(I/O)
            8     |     21(I/O),48(I/O)
            9     |     17(CLK1/In)   
           10     |     50(In)        
           11     |     54(In)        
           12     |     55(In)        
           13     |     56(In)        
           14     |     57(I/O)       
           15     |     58(I/O)       
           16     |     nc            
           17     |     nc            
           18     |     nc            
           19     |     nc            
           20     |     1(GND),35(GND)
           21     |     19(CLK2/In)   
           22     |     nc            
           23     |     nc          
           24     |     nc          
           25     |     nc          
           26     |     nc          
           27     |     nc       
           28     |     nc      
           29     |     nc        
           30     |     nc        
           31     |     nc        
           32     |     18(VCC),52(VCC) 
           33     |     5(I/O)        
           34     |     4(I/O)        
           35     |     3(I/O)        
           36     |     2(I/O)        
           37     |     68(I/O)       
           38     |     67(I/O)       
           39     |     66(I/O)       
           40     |     65(I/O)       

These pins on PLCC socket are not connected:
6-9,12-16,22,27-34,36-43,51,53