This table identifies operations for the instruction groups which contain
the opcode in bits 3-5 of the second byte (normally the addressing mode
byte).
                                                                 
 md000rm md001rm md010rm md011rm md100rm md101rm md110rm md111rm 
                                                                        
ArOp1    ADD     OR      ADC     SBB     AND     SUB     XOR     CMP    
                                                                        
ArOp2    ADD             ADC     SBB             SUB             CMP    
                                                                        
ShftOp   ROL     ROR     RCL     RCR    SHL/SAL  SHR             RAR    
                                                                        
Grp1     TEST            NOT     NEG     MUL     IMUL    DIV     IDIV   
                                                                        
Grp2     INC      DEC   CALL nr CALL fr JMP nr  JMP far  PUSH           
                                                                        
Grp3     INC      DEC                                                   
                                                                        

Secondary Opcode Space