Intel 80286, 80287 manual Rb = Rw =, Reg =, Mod=OO Mod=01 Mod=10 Mod=11, BX + D8 SI +, BX + 01 +

Rb =

Rw =

REG =

mod=OO

mod=01

mod=10

mod=11

NOTES:

		THE 80286 INSTRUCTION SET
		Table B·1. ModRM Values
AL	CL	OL	BL	AH	CH	OH	BH
AX	CX	OX	BX	SP	BP	SI	01
0	1	2	3	4	5	6	7
		ModRM values						Effective address
00	08	10	18	20	28	30	38	[BX +	SI]
01	09	11	19	21	29	31	39	[BX +	01]
02	OA	12	1A	22	2A	32	3A	[BP +	SI]
03	OB	13	1B	23	2B	33	3B	[BP +	01]
04	OC	14	1C	24	2C	34	3C	[SI]
05	00	15	10	25	20	35	30	[01]
06	OE	16	1E	26	2E	36	3E	016 (simple var)
07	OF	17	1F	27	2F	37	3F	[BX]
40	48	50	58	60	68	70	78	[BX +	SI] +		OS(l)
41	49	51	59	61	69	71	79	[BX + 01] + OS
42	4A	52	5A	62	6A	72	7A	[BP + SI] + OS
43	4B	53	5B	63	6B	73	7B	[BP +	01] +		OS
44	4C	54	5C	64	6C	74	7C	[SI] +	OS
45	40	55	50	65	60	75	70	[01] +	OS
46	4E	56	5E	66	6E	76	7E	[BP] +	DS(2)
47	4F	57	5F	67	6F	77	7F	[BX] + D8
SO	88	90	98	AO	AS	BO	BS	[BX +	SI] +		016(3)
81	89	91	99	A1	A9	B1	B9	[BX + 01] + 016
S2	8A	92	9A	A2	AA	B2	BA	[BP +SI] +			016
S3	SB	93	9B	A3	AB	B3	BB	[BP + 01] + 016
S4	SC	94	9C	A4	AC	B4	BC	[SI] +	016
S5	SO	95	90	A5	AO	B5	BO	[01] +	016
S6	SE	96 .	9E	A6	AE	B6	BE	[BP] +	016(2)
87	SF	97	9F	A7	AF	B7	BF	[BX] +	016
CO	CS	00	OS	EO	ES	FO	FS	Ew=AX		Eb=AL
C1	C9	01	09	E1	E9	F1	F9	Ew=CX		Eb=CL
C2	CA	02	OA	E2	EA	F2	FA	Ew=OX		Eb=OL
C3	CB	03	OB	E3	EB	F3	FB	Ew=BX		Eb=BL
C4	CC	04	OC	E4	EC	F4	FC	Ew=SP		Eb=AH
C5	CO	05	00	E5	EO	F5	FO	Ew=BP		Eb=CH
C6	CE	06	OE	E6	EE	F6	FE	Ew=SI		Eb=OH
C7	CF	07	OF	E7	EF	F7	FF	Ew=OI		Eb=BH

1.OS denotes an 8-bit displacement following the ModRM byte that is sign-extended and added to the index.

2.Oefault segment register is SS for effective addresses containing a BP index; OS is for other memory effective addresses.

3.016 denotes the 16-bit displacement following the ModRM byte that is added to the index.

B-3