                                                              6-8

Opcodes     Instruction    Description

37          AAA            ASCII adjust AL (carry into AH) after addition
D5 0A       AAD            ASCII adjust before division (AX = 10*AH + AL)
D4 0A       AAM            ASCII adjust after multiply (AL/10: AH=Quo AL=Rem)
3F          AAS            ASCII adjust AL (borrow from AH) after subtraction
14 ib       ADC AL,ib      Add with carry immediate byte into AL
15 iw       ADC AX,iw      Add with carry immediate word into AX
80 /2 ib    ADC eb,ib      Add with carry immediate byte into EA byte
10 /r       ADC eb,rb      Add with carry byte register into EA byte
83 /2 ib    ADC ew,ib      Add with carry immediate byte into EA word
81 /2 iw    ADC ew,iw      Add with carry immediate word into EA word
11 /r       ADC ew,rw      Add with carry word register into EA word
12 /r       ADC rb,eb      Add with carry EA byte into byte register
13 /r       ADC rw,ew      Add with carry EA word into word register

04 ib       ADD AL,ib      Add immediate byte into AL
05 iw       ADD AX,iw      Add immediate word into AX
80 /0 ib    ADD eb,ib      Add immediate byte into EA byte
00 /r       ADD eb,rb      Add byte register into EA byte
83 /0 ib    ADD ew,ib      Add immediate byte into EA word
81 /0 iw    ADD ew,iw      Add immediate word into EA word
01 /r       ADD ew,rw      Add word register into EA word
02 /r       ADD rb,eb      Add EA byte into byte register
03 /r       ADD rw,ew      Add EA word into word register
0F 20      #ADD4S          Add CL nibbles BCD from DS:SI into ES:DI (CL even,NZ)

24 ib       AND AL,ib      Logical-AND immediate byte into AL
25 iw       AND AX,iw      Logical-AND immediate word into AX
80 /4 ib    AND eb,ib      Logical-AND immediate byte into EA byte
20 /r       AND eb,rb      Logical-AND byte register into EA byte
83 /4 ib    AND ew,ib      Logical-AND immediate byte into EA word
81 /4 iw    AND ew,iw      Logical-AND immediate word into EA word
21 /r       AND ew,rw      Logical-AND word register into EA word
22 /r       AND rb,eb      Logical-AND EA byte into byte register
23 /r       AND rw,ew      Logical-AND EA word into word register
63 /r      *ARPL ew,rw     Adjust RPL of EA word not smaller than RPL of rw

62 /r      *BOUND rw,md    INT 5 if rw not between [md] and [md+2] inclusive
9A cd       CALL cd        Call far segment, immediate 4-byte address
E8 cw       CALL cw        Call near, offset relative to next instruction
FF /3       CALL ed        Call far segment, address at EA doubleword
FF /2       CALL ew        Call near, offset absolute at EA word
0F FF ib   #CALL80 ib      Call 8080-emulation code at INT number ib
98          CBW            Convert byte into word (AH = top bit of AL)
F8          CLC            Clear carry flag
FC          CLD            Clear direction flag so SI and DI will increment
FA          CLI            Clear interrupt enable flag; interrupts disabled
                                                              6-9

0F 12/0    #CLRBIT eb,CL   Clear bit CL of eb
0F 13/0    #CLRBIT ew,CL   Clear bit CL of ew
0F 1A/0 ib #CLRBIT eb,ib   Clear bit ib of eb
0F 1B/0 ib #CLRBIT ew,ib   Clear bit ib of ew
0F 06      *CLTS           Clear task switched flag
F5          CMC            Complement carry flag
3C ib       CMP AL,ib      Subtract immediate byte from AL for flags only
3D iw       CMP AX,iw      Subtract immediate word from AX for flags only
80 /7 ib    CMP eb,ib      Subtract immediate byte from EA byte for flags only
38 /r       CMP eb,rb      Subtract byte register from EA byte for flags only
83 /7 ib    CMP ew,ib      Subtract immediate byte from EA word for flags only
81 /7 iw    CMP ew,iw      Subtract immediate word from EA word for flags only
39 /r       CMP ew,rw      Subtract word register from EA word for flags only
3A /r       CMP rb,eb      Subtract EA byte from byte register for flags only
3B /r       CMP rw,ew      Subtract EA word from word register for flags only

0F 26      #CMP4S          Compare CL nibbles CD at DS:SI from ES:DI (CL even,NZ)
A6          CMPS mb,mb     Compare bytes ES:[DI] from [SI], advance SI and DI
A7          CMPS mw,mw     Compare words ES:[DI] from [SI], advance SI and DI
A6          CMPSB          Compare bytes ES:[DI] from DS:[SI], advance SI and DI
A7          CMPSW          Compare words ES:[DI] from DS:[SI], advance SI and DI
99          CWD            Convert word to doubleword (DX = top bit of AX)

27          DAA            Decimal adjust AL after addition
2F          DAS            Decimal adjust AL after subtraction
FE /1       DEC eb         Decrement EA byte by 1
FF /1       DEC ew         Decrement EA word by 1
48+rw       DEC rw         Decrement word register by 1
F6 /6       DIV eb         Unsigned divide AX by EA byte (AL=Quo AH=Rem)
F7 /6       DIV ew         Unsigned divide DXAX by EA word (AX=Quo DX=Rem)
C8 iw 00   *ENTER iw,0     Make stack frame, iw bytes local storage, 0 levels
C8 iw 01   *ENTER iw,1     Make stack frame, iw bytes local storage, 1 level
C8 iw ib   *ENTER iw,ib    Make stack frame, iw bytes local storage, ib levels
            Fany           Floating point set is in Chapter 7
F4          HLT            Halt

F6 /7       IDIV eb        Signed divide AX by EA byte (AL=Quo AH=Rem)
F7 /7       IDIV ew        Signed divide DXAX by EA word (AX=Quo DX=Rem)
F6 /5       IMUL eb        Signed multiply (AX = AL * EA byte)
F7 /5       IMUL ew        Signed multiply (DXAX = AX * EA word)
6B /r ib   *IMUL rw,ib     Signed multiply immediate byte into word register
69 /r iw   *IMUL rw,iw     Signed multiply immediate word into word register
69 /r iw   *IMUL rw,ew,iw  Signed multiply (rw = EA word * immediate word)
6B /r ib   *IMUL rw,ew,ib  Signed multiply (rw = EA word * immediate byte)

E4 ib       IN AL,ib       Input byte from immediate port into AL
EC          IN AL,DX       Input byte from port DX into AL
E5 ib       IN AX,ib       Input word from immediate port into AX
ED          IN AX,DX       Input word from port DX into AX

FE /0       INC eb         Increment EA byte by 1
FF /0       INC ew         Increment EA word by 1
40+rw       INC rw         Increment word register by 1
6C         *INS eb,DX      Input byte from port DX into [DI]
6D         *INS ew,DX      Input word from port DX into [DI]
6C         *INSB           Input byte from port DX into ES:[DI]
6D         *INSW           Input word from port DX into ES:[DI]
                                                             6-10

CC          INT 3          Interrupt 3 (trap to debugger) (far call, with flags
CD ib       INT ib         Interrupt numbered by immediate byte     pushed first)
CE          INTO           Interrupt 4 if overflow flag is 1
CF          IRET           Interrupt return (far return and pop flags)

77 cb       JA cb          Jump short if above (CF=0 and ZF=0)    above=UNSIGNED
73 cb       JAE cb         Jump short if above or equal (CF=0)
72 cb       JB cb          Jump short if below (CF=1)             below=UNSIGNED
76 cb       JBE cb         Jump short if below or equal (CF=1 or ZF=1)
72 cb       JC cb          Jump short if carry (CF=1)
E3 cb       JCXZ cb        Jump short if CX register is zero
74 cb       JE cb          Jump short if equal (ZF=1)
7F cb       JG cb          Jump short if greater (ZF=0 and SF=OF)  greater=SIGNED
7D cb       JGE cb         Jump short if greater or equal (SF=OF)
7C cb       JL cb          Jump short if less (SF/=OF)                less=SIGNED
7E cb       JLE cb         Jump short if less or equal (ZF=1 or SF/=OF)

EB cb       JMP cb         Jump short (signed byte relative to next instruction)
EA cd       JMP cd         Jump far (4-byte immediate address)
E9 cw       JMP cw         Jump near (word offset relative to next instruction)
FF /4       JMP ew         Jump near to EA word (absolute offset)
FF /5       JMP md         Jump far (4-byte address in memory doubleword)

76 cb       JNA cb         Jump short if not above (CF=1 or ZF=1)
72 cb       JNAE cb        Jump short if not above or equal (CF=1)
73 cb       JNB cb         Jump short if not below (CF=0)
77 cb       JNBE cb        Jump short if not below or equal (CF=0 and ZF=0)
73 cb       JNC cb         Jump short if not carry (CF=0)
75 cb       JNE cb         Jump short if not equal (ZF=0)
7E cb       JNG cb         Jump short if not greater (ZF=1 or SF/=OF)
7C cb       JNGE cb        Jump short if not greater or equal (SF/=OF)
7D cb       JNL cb         Jump short if not less (SF=OF)
7F cb       JNLE cb        Jump short if not less or equal (ZF=0 and SF=OF)

71 cb       JNO cb         Jump short if not overflow (OF=0)
7B cb       JNP cb         Jump short if not parity (PF=0)
79 cb       JNS cb         Jump short if not sign (SF=0)
75 cb       JNZ cb         Jump short if not zero (ZF=0)
70 cb       JO cb          Jump short if overflow (OF=1)
7A cb       JP cb          Jump short if parity (PF=1)
7A cb       JPE cb         Jump short if parity even (PF=1)
7B cb       JPO cb         Jump short if parity odd (PF=0)
78 cb       JS cb          Jump short if sign (SF=1)
74 cb       JZ cb          Jump short if zero (ZF=1)

9F          LAHF           Load: AH = flags  SF ZF xx AF xx PF xx CF
0F 02 /r   *LAR rw,ew      Load: high(rw) = Access Rights byte, selector ew
C5 /r       LDS rw,ed      Load EA doubleword into DS and word register
8D /r       LEA rw,m       Calculate EA offset given by m, place in rw
C9         *LEAVE          Set SP to BP, then POP BP (reverses previous ENTER)
C4 /r       LES rw,ed      Load EA doubleword into ES and word register

0F 01 /2   *LGDT m         Load 6 bytes at m into Global Descriptor Table reg
0F 01 /3   *LIDT m         Load 6 bytes at m into Interrupt Descriptor Table reg
0F 00 /2   *LLDT ew        Load selector ew into Local Descriptor Table reg
0F 01 /6   *LMSW ew        Load EA word into Machine Status Word
F0          LOCK (prefix)  Assert BUSLOCK signal for the next instruction
                                                             6-11

0F 33/r    #LODBITS rb,rb  Load AX with DS:SI,bit rb (incr. SI,rb), rb+1 bits
0F 3B/0 ib #LODBITS rb,ib  Load AX with DS:SI,bit rb (incr. SI,rb), ib+1 bits
AC          LODS mb        Load byte [SI] into AL, advance SI
AD          LODS mw        Load word [SI] into AX, advance SI
AC          LODSB          Load byte [SI] into AL, advance SI
AD          LODSW          Load word [SI] into AX, advance SI

E2 cb       LOOP cb        noflags DEC CX; jump short if CX/=0
E1 cb       LOOPE cb       noflags DEC CX; jump short if CX/=0 and equal (ZF=1)
E0 cb       LOOPNE cb      noflags DEC CX; jump short if CX/=0 and not equal
E0 cb       LOOPNZ cb      noflags DEC CX; jump short if CX/=0 and ZF=0
E1 cb       LOOPZ cb       noflags DEC CX; jump short if CX/=0 and zero (ZF=1)
0F 03 /r   *LSL rw,ew      Load: rw = Segment Limit, selector ew
0F 00 /3   *LTR ew         Load EA word into Task Register

A0 iw       MOV AL,xb      Move byte variable (offset iw) into AL
A1 iw       MOV AX,xw      Move word variable (offset iw) into AX
8E /3       MOV DS,mw      Move memory word into DS
8E /3       MOV DS,rw      Move word register into DS
C6 /0 ib    MOV eb,ib      Move immediate byte into EA byte
88 /r       MOV eb,rb      Move byte register into EA byte
8E /0       MOV ES,mw      Move memory word into ES
8E /0       MOV ES,rw      Move word register into ES

8C /1       MOV ew,CS      Move CS into EA word
8C /3       MOV ew,DS      Move DS into EA word
C7 /0 iw    MOV ew,iw      Move immediate word into EA word
8C /0       MOV ew,ES      Move ES into EA word
89 /r       MOV ew,rw      Move word register into EA word
8C /2       MOV ew,SS      Move SS into EA word
B0+rb ib    MOV rb,ib      Move immediate byte into byte register
8A /r       MOV rb,eb      Move EA byte into byte register
B8+rw iw    MOV rw,iw      Move immediate word into word register
8B /r       MOV rw,ew      Move EA word into word register

8E /2       MOV SS,mw      Move memory word into SS
8E /2       MOV SS,rw      Move word register into SS
A2 iw       MOV xb,AL      Move AL into byte variable (offset iw)
A3 iw       MOV xw,AX      Move AX into word register (offset iw)
A4          MOVS mb,mb     Move byte [SI] to ES:[DI], advance SI and DI
A5          MOVS mw,mw     Move word [SI] to ES:[DI], advance SI and DI
A4          MOVSB          Move byte DS:[SI] to ES:[DI], advance SI and DI
A5          MOVSW          Move word DS:[SI] to ES:[DI], advance SI and DI
                                                             6-12

F6 /4       MUL eb         Unsigned multiply (AX = AL * EA byte)
F7 /4       MUL ew         Unsigned multiply (DXAX = AX * EA word)
F6 /3       NEG eb         Two's complement negate EA byte
F7 /3       NEG ew         Two's complement negate EA word
            NIL (prefix)   Special "do-nothing" opcode assembles no code
90          NOP            No Operation
F6 /2       NOT eb         Reverse each bit of EA byte
F7 /2       NOT ew         Reverse each bit of EA word
0F 16/0    #NOTBIT eb,CL   Complement bit CL of eb
0F 17/0    #NOTBIT ew,CL   Complement bit CL of ew
0F 1E/0 ib #NOTBIT eb,ib   Complement bit ib of eb
0F 1F/0 ib #NOTBIT ew,ib   Complement bit ib of ew

0C ib       OR AL,ib       Logical-OR immediate byte into AL
0D iw       OR AX,iw       Logical-OR immediate word into AX
80 /1 ib    OR eb,ib       Logical-OR immediate byte into EA byte
08 /r       OR eb,rb       Logical-OR byte register into EA byte
83 /1 ib    OR ew,ib       Logical-OR immediate byte into EA word
81 /1 iw    OR ew,iw       Logical-OR immediate word into EA word
09 /r       OR ew,rw       Logical-OR word register into EA word
0A /r       OR rb,eb       Logical-OR EA byte into byte register
0B /r       OR rw,ew       Logical-OR EA word into word register

E6 ib       OUT ib,AL      Output byte AL to immediate port number ib
E7 ib       OUT ib,AX      Output word AX to immediate port number ib
EE          OUT DX,AL      Output byte AL to port number DX
EF          OUT DX,AX      Output word AX to port number DX
6E         *OUTS DX,eb     Output byte [SI] to port number DX, advance SI
6F         *OUTS DX,ew     Output word [SI] to port number DX, advance SI
6E         *OUTSB          Output byte DS:[SI] to port number DX, advance SI
6F         *OUTSW          Output word DS:[SI] to port number DX, advance SI

1F          POP DS         Set DS to top of stack, increment SP by 2
07          POP ES         Set ES to top of stack, increment SP by 2
8F /0       POP mw         Set memory word to top of stack, increment SP by 2
58+rw       POP rw         Set word register to top of stack, increment SP by 2
17          POP SS         Set SS to top of stack, increment SP by 2
61         *POPA           Pop DI,SI,BP,SP,BX,DX,CX,AX (SP value is ignored)
9D          POPF           Set flags register to top of stack, increment SP by 2

0E          PUSH CS        Set [SP-2] to CS, then decrement SP by 2
1E          PUSH DS        Set [SP-2] to DS, then decrement SP by 2
06          PUSH ES        Set [SP-2] to ES, then decrement SP by 2
6A ib      *PUSH ib        Push sign-extended immediate byte
68 iw      *PUSH iw        Set [SP-2] to immediate word, then decrement SP by 2
FF /6       PUSH mw        Set [SP-2] to memory word, then decrement SP by 2
50+rw       PUSH rw        Set [SP-2] to word register, then decrement SP by 2
16          PUSH SS        Set [SP-2] to SS, then decrement SP by 2
60         *PUSHA          Push AX,CX,DX,BX,original SP,BP,SI,DI
9C          PUSHF          Set [SP-2] to flags register, then decrement SP by 2

D0 /2       RCL eb,1       Rotate 9-bit quantity (CF, EA byte) left once
D2 /2       RCL eb,CL      Rotate 9-bit quantity (CF, EA byte) left CL times
C0 /2 ib   *RCL eb,ib      Rotate 9-bit quantity (CF, EA byte) left ib times
D1 /2       RCL ew,1       Rotate 17-bit quantity (CF, EA word) left once
D3 /2       RCL ew,CL      Rotate 17-bit quantity (CF, EA word) left CL times
C1 /2 ib   *RCL ew,ib      Rotate 17-bit quantity (CF, EA word) left ib times
                                                             6-13

D0 /3       RCR eb,1       Rotate 9-bit quantity (CF, EA byte) right once
D2 /3       RCR eb,CL      Rotate 9-bit quantity (CF, EA byte) right CL times
C0 /3 ib   *RCR eb,ib      Rotate 9-bit quantity (CF, EA byte) right ib times
D1 /3       RCR ew,1       Rotate 17-bit quantity (CF, EA word) right once
D3 /3       RCR ew,CL      Rotate 17-bit quantity (CF, EA word) right CL times
C1 /3 ib   *RCR ew,ib      Rotate 17-bit quantity (CF, EA word) right ib times

F3          REP (prefix)   Repeat following MOVS,LODS,STOS,INS, or OUTS CX times
65         #REPC (prefix)  Repeat following CMPS or SCAS CX times or until CF=0
F3          REPE (prefix)  Repeat following CMPS or SCAS CX times or until ZF=0
64         #REPNC (prfix)  Repeat following CMPS or SCAS CX times or until CF=1
F2          REPNE (prfix)  Repeat following CMPS or SCAS CX times or until ZF=1
F2          REPNZ (prfix)  Repeat following CMPS or SCAS CX times or until ZF=1
F3          REPZ (prefix)  Repeat following CMPS or SCAS CX times or until ZF=0

CB          RETF           Return to far caller (pop offset, then seg)
C3          RET            Return to near caller (pop offset only)
CA iw       RETF iw        RET (far), pop offset, seg, iw bytes
C2 iw       RET iw         RET (near), pop offset, iw bytes pushed before Call

D0 /0       ROL eb,1       Rotate 8-bit EA byte left once
D2 /0       ROL eb,CL      Rotate 8-bit EA byte left CL times
C0 /0 ib   *ROL eb,ib      Rotate 8-bit EA byte left ib times
D1 /0       ROL ew,1       Rotate 16-bit EA word left once
D3 /0       ROL ew,CL      Rotate 16-bit EA word left CL times
C1 /0 ib   *ROL ew,ib      Rotate 16-bit EA word left ib times
0F 28/0    #ROL4 eb        Rotate nibbles: Heb=Leb   HAL,Leb=LAL  LAL=Heb

D0 /1       ROR eb,1       Rotate 8-bit EA byte right once
D2 /1       ROR eb,CL      Rotate 8-bit EA byte right CL times
C0 /1 ib   *ROR eb,ib      Rotate 8-bit EA byte right ib times
D1 /1       ROR ew,1       Rotate 16-bit EA word right once
D3 /1       ROR ew,CL      Rotate 16-bit EA word right CL times
C1 /1 ib   *ROR ew,ib      Rotate 16-bit EA word right ib times
0F 2A/0    #ROR4 eb        Rotate nibbles: Leb=Heb   Heb=LAL  AL=eb

9E          SAHF           Store AH into flags  SF ZF xx AF xx PF xx CF
D0 /4       SAL eb,1       Multiply EA byte by 2, once
D2 /4       SAL eb,CL      Multiply EA byte by 2, CL times
C0 /4 ib   *SAL eb,ib      Multiply EA byte by 2, ib times
D1 /4       SAL ew,1       Multiply EA word by 2, once
D3 /4       SAL ew,CL      Multiply EA word by 2, CL times
C1 /4 ib   *SAL ew,ib      Multiply EA word by 2, ib times

D0 /7       SAR eb,1       Signed divide EA byte by 2, once
D2 /7       SAR eb,CL      Signed divide EA byte by 2, CL times
C0 /7 ib   *SAR eb,ib      Signed divide EA byte by 2, ib times
D1 /7       SAR ew,1       Signed divide EA word by 2, once
D3 /7       SAR ew,CL      Signed divide EA word by 2, CL times
C1 /7 ib   *SAR ew,ib      Signed divide EA word by 2, ib times
                                                             6-14

1C ib       SBB AL,ib      Subtract with borrow immediate byte from AL
1D iw       SBB AX,iw      Subtract with borrow immediate word from AX
80 /3 ib    SBB eb,ib      Subtract with borrow immediate byte from EA byte
18 /r       SBB eb,rb      Subtract with borrow byte register from EA byte
83 /3 ib    SBB ew,ib      Subtract with borrow immediate byte from EA word
81 /3 iw    SBB ew,iw      Subtract with borrow immediate word from EA word
19 /r       SBB ew,rw      Subtract with borrow word register from EA word
1A /r       SBB rb,eb      Subtract with borrow EA byte from byte register
1B /r       SBB rw,ew      Subtract with borrow EA word from word register

AE          SCAS mb        Compare bytes AL - ES:[DI], advance DI
AF          SCAS mw        Compare words AL - ES:[DI], advance DI
AE          SCASB          Compare bytes AX - ES:[DI], advance DI
AF          SCASW          Compare words AX - ES:[DI], advance DI

0F 14/0    #SETBIT eb,CL   Set bit CL of eb
0F 15/0    #SETBIT ew,CL   Set bit CL of ew
0F 1C/0 ib #SETBIT eb,ib   Set bit ib of eb
0F 1D/0 ib #SETBIT ew,ib   Set bit ib of ew
0F 01 /0   *SGDT m         Store 6-byte Global Descriptor Table register to M

D0 /4       SHL eb,1       Multiply EA byte by 2, once
D2 /4       SHL eb,CL      Multiply EA byte by 2, CL times
C0 /4 ib   *SHL eb,ib      Multiply EA byte by 2, ib times
D1 /4       SHL ew,1       Multiply EA word by 2, once
D3 /4       SHL ew,CL      Multiply EA word by 2, CL times
C1 /4 ib   *SHL ew,ib      Multiply EA word by 2, ib times
D0 /5       SHR eb,1       Unsigned divide EA byte by 2, once
D2 /5       SHR eb,CL      Unsigned divide EA byte by 2, CL times
C0 /5 ib   *SHR eb,ib      Unsigned divide EA byte by 2, ib times
D1 /5       SHR ew,1       Unsigned divide EA word by 2, once
D3 /5       SHR ew,CL      Unsigned divide EA word by 2, CL times
C1 /5 ib   *SHR ew,ib      Unsigned divide EA word by 2, ib times

0F 01 /1   *SIDT m         Store 6-byte Interrupt Descriptor Table register to M
0F 00 /0   *SLDT ew        Store Local Descriptor Table register to EA word
0F 01 /4   *SMSW ew        Store Machine Status Word to EA word
F9          STC            Set carry flag
FD          STD            Set direction flag so SI and DI will decrement
FB          STI            Set interrupt enable flag, interrupts enabled

0F 31/r    #STOBITS rb,rb  Store AX to ES:DI,bit rb (incr. DI,rb), rb+1 bits
0F 39/0 ib #STOBITS rb,ib  Store AX to ES:DI,bit rb (incr. DI,rb), ib+1 bits
AA          STOS mb        Store AL to byte [DI], advance DI
AB          STOS mw        Store AX to word [DI], advance DI
AA          STOSB          Store AL to byte ES:[DI], advance DI
AB          STOSW          Store AX to word ES:[DI], advance DI
0F 00 /1   *STR ew         Store Task Register to EA word
                                                             6-15

2C ib       SUB AL,ib      Subtract immediate byte from AL
2D iw       SUB AX,iw      Subtract immediate word from AX
80 /5 ib    SUB eb,ib      Subtract immediate byte from EA byte
28 /r       SUB eb,rb      Subtract byte register from EA byte
83 /5 ib    SUB ew,ib      Subtract immediate byte from EA word
81 /5 iw    SUB ew,iw      Subtract immediate word from EA word
29 /r       SUB ew,rw      Subtract word register from EA word
2A /r       SUB rb,eb      Subtract EA byte from byte register
2B /r       SUB rw,ew      Subtract EA word from word register
0F 22      #SUB4S          Sub CL nibbles BCD at DS:SI from ES:DI (CL even,NZ)

A8 ib       TEST AL,ib     AND immediate byte into AL for flags only
A9 iw       TEST AX,iw     AND immediate word into AX for flags only
F6 /0 ib    TEST eb,ib     AND immediate byte into EA byte for flags only
84 /r       TEST eb,rb     AND byte register into EA byte for flags only
F7 /0 iw    TEST ew,iw     AND immediate word into EA word for flags only
85 /r       TEST ew,rw     AND word register into EA word for flags only
84 /r       TEST rb,eb     AND EA byte into byte register for flags only
85 /r       TEST rw,ew     AND EA word into word register for flags only

0F 10/0    #TESTBIT eb,CL  Test bit CL of eb, set Z flag
0F 11/0    #TESTBIT ew,CL  Test bit CL of ew, set Z flag
0F 18/0 ib #TESTBIT eb,ib  Test bit ib of eb, set Z flag
0F 19/0 ib #TESTBIT ew,ib  Test bit ib of ew, set Z flag
9B          WAIT           Wait until BUSY pin is inactive (HIGH)
0F 00 /4   *VERR ew        Set ZF=1 if segment can be read, selector ew
0F 00 /5   *VERW ew        Set ZF=1 if segment can be written to, selector ew

9r          XCHG AX,rw     Exchange word register with AX
86 /r       XCHG eb,rb     Exchange byte register with EA byte
87 /r       XCHG ew,rw     Exchange word register with EA word
86 /r       XCHG rb,eb     Exchange EA byte with byte register
9r          XCHG rw,AX     Exchange  with word register
87 /r       XCHG rw,ew     Exchange EA word with word register

D7          XLAT mb        Set AL to memory byte [BX + unsigned AL]
D7          XLATB          Set AL to memory byte DS:[BX + unsigned AL]
34 ib       XOR AL,ib      Exclusive-OR immediate byte into AL
35 iw       XOR AX,iw      Exclusive-OR immediate word into AX
80 /6 ib    XOR eb,ib      Exclusive-OR immediate byte into EA byte
30 /r       XOR eb,rb      Exclusive-OR byte register into EA byte
83 /6 ib    XOR ew,ib      Exclusive-OR immediate byte into EA word
81 /6 iw    XOR ew,iw      Exclusive-OR immediate word into EA word
31 /r       XOR ew,rw      Exclusive-OR word register into EA word
32 /r       XOR rb,eb      Exclusive-OR EA byte into byte register
33 /r       XOR rw,ew      Exclusive-OR EA word into word register

*  Starred forms will not execute on 8086/8088!  See note at top of chart.
#  These instructions work only on NEC chips!  See note at top of chart.

