High Level Assembler - Opcodes overview

The first table below lists the opcodes in the original S/360 IBM mainframe processor implementation, including all dropped instructions and a selection of the instructions that were later added. The other two tables below list selected opcodes for current mainframe processors.
Colors have been added in these tables to show the changes in the design and - above all - the orthogonality of the basic design, which shows in both horizontal and vertical stratification.
A legend is provided below each table.

Both selection and categorization (in the second and third tables) have been done by the author; no involvement by IBM is implied in any way. The selection of opcodes is the same for all three tables, except that the first table contains some opcodes that have been omitted from the other two. However, the opcodes not shown are mainly those that are rarely used, and did not fit in very well with horizontal stratification. Thus, the exceptions - caused by additions after the original design of the the early 1960s was implemented - are much more apparent in the vertical stratification.

The first table shows the complete original set, including instructions that were later dropped. It also shows all instructions present in the other two tables.

The second table shows horizontal stratification, which organizes instructions mainly by data type. It is easy to see that many of the newer instructions have been added in positions that are consistent with the existing stratification. However, some of the newer instructions appear to have been placed at randomly chosen positions. Not many of these exceptions appear in the table; this results (partly) from the way I constructed the table.

The third table shows vertical stratification, which organizes instructions mainly by type of operation. The background colors signify the type of operation, and the text color further distinguishes the type of operation, e.g., a white background designates load-type operations, green text is for load-negative opcodes, black text is for load-positive operations, etc.

In the third table it is much more clearly visible that IBM has tried to insert new opcodes in an appropriate position, when one was available. Nevertheless, quite a few of the newer opcodes appear in seemingly random positions.

The table shows a few noteworthy implementation details. The first is that some instructions skip over a few lines, e.g., the and-instructions appear on lines 1, 5, 9 and D which are all four lines apart.

The second detail is that even though this table is designed to show the vertical stratification, some of the horizontal stratification is still visible, e.g. the branch-on-index and the shifting instructions on line 8.

Original Implementation.

	0	1	2	3	4	5	6	7	8	9	A	B	C	D	E	F
0					SPM	BALR	BCTR	BCR	SSK	ISK	SVC	BSM	BASSM	BASR	MVCL	CLCL
1	LPR	LNR	LTR	LCR	NR	CLR	OR	XR	LR	CR	AR	SR	MR	DR	ALR	SLR
2	LPDR	LNDR	LTDR	LCDR	HDR	LDXR	MXR	MXDR	LDR	CDR	ADR	SDR	MDR	DDR	AWR	SWR
3	LPER	LNER	LTER	LCER	HER	LEDR	AXR	SXR	LER	CER	AER	SER	MER	DER	AUR	SUR
4	STH	LA	STC	IC	EX	BAL	BCT	BC	LH	CH	AH	SH	MH	BAS	CVD	CVB
5	ST	LAE			N	CL	O	X	L	C	A	S	M	D	AL	SL
6	STD							MXD	LD	CD	AD	SD	MD	DD	AW	SW
7	STE	MS							LE	CE	AE	SE	ME	DE	AU	SU
8	SSM		LPSW	DIAG	WRD BRXH	RDD BRXLE	BXH	BXLE	SRL	SLL	SRA	SLA	SRDL	SLDL	SRDA	SLDA
9	STM	TM	MVI	TS	NI	CLI	OI	XI	LM		LAM	STAM	SIO	TIO	HIO	TCH
A									MVCLE	CLCLE						MC
B		LRA					STCTL	LCTL			CS	CDS		CLM	STCM	ICM
C
D		MVN	MVC	MVZ	NC	CLC	OC	XC		MVCK	MVCP	MVCS	TR	TRT	ED	EDMK
E		PKU	UNPKU						MVCIN	PKA	UNPKA				PLO	LMD
F	SRP	MVO	PACK	UNPK					ZAP	CP	AP	SP	MP	DP

Legend

Black without text: Not assigned
Blue with White text: Instructions in original set, still valid
Red with Black text: Instructions in original set, no longer valid
Yellow with Black text: New instructions, not in original set

Horizontal Stratification.

	0	1	2	3	4	5	6	7	8	9	A	B	C	D	E	F
0					SPM	BALR	BCTR	BCR			SVC	BSM	BASSM	BASR	MVCL	CLCL
1	LPR	LNR	LTR	LCR	NR	CLR	OR	XR	LR	CR	AR	SR	MR	DR	ALR	SLR
2	LPDR	LNDR	LTDR	LCDR	HDR	LDXR	MXR	MXDR	LDR	CDR	ADR	SDR	MDR	DDR	AWR	SWR
3	LPER	LNER	LTER	LCER	HER	LEDR	AXR	SXR	LER	CER	AER	SER	MER	DER	AUR	SUR
4	STH	LA	STC	IC	EX	BAL	BCT	BC	LH	CH	AH	SH	MH	BAS	CVD	CVB
5	ST	LAE			N	CL	O	X	L	C	A	S	M	D	AL	SL
6	STD							MXD	LD	CD	AD	SD	MD	DD	AW	SW
7	STE	MS							LE	CE	AE	SE	ME	DE	AU	SU
8					BRXH	BRXLE	BXH	BXLE	SRL	SLL	SRA	SLA	SRDL	SLDL	SRDA	SLDA
9	STM	TM	MVI	TS	NI	CLI	OI	XI	LM		LAM	STAM
A									MVCLE	CLCLE						MC
B		LRA					STCTL	LCTL			CS	CDS		CLM	STCM	ICM
C
D		MVN	MVC	MVZ	NC	CLC	OC	XC		MVCK	MVCP	MVCS	TR	TRT	ED	EDMK
E		PKU	UNPKU						MVCIN	PKA	UNPKA				PLO	LMD
F	SRP	MVO	PACK	UNPK					ZAP	CP	AP	SP	MP	DP

Legend

Black without text: Not assigned / Not Shown
Blue with Black text: Moving Data
Brown with Black text: Boolean Logic
Green with Black text: Floating point Operations
Grey with Black text: Character Operations
Magenta with Black text: Bit Operations
Pink with Black text: Program Flow Control
Red with Black text: Packed Operations
Yellow with Black text: Integer Calculus
White with Black text: Other Operations

Vertical Stratification.

	0	1	2	3	4	5	6	7	8	9	A	B	C	D	E	F
0					SPM	BALR	BCTR	BCR			SVC	BSM	BASSM	BASR	MVCL	CLCL
1	LPR	LNR	LTR	LCR	NR	CLR	OR	XR	LR	CR	AR	SR	MR	DR	ALR	SLR
2	LPDR	LNDR	LTDR	LCDR	HDR	LDXR	MXR	MXDR	LDR	CDR	ADR	SDR	MDR	DDR	AWR	SWR
3	LPER	LNER	LTER	LCER	HER	LEDR	AXR	SXR	LER	CER	AER	SER	MER	DER	AUR	SUR
4	STH	LA	STC	IC	EX	BAL	BCT	BC	LH	CH	AH	SH	MH	BAS	CVD	CVB
5	ST	LAE			N	CL	O	X	L	C	A	S	M	D	AL	SL
6	STD							MXD	LD	CD	AD	SD	MD	DD	AW	SW
7	STE	MS							LE	CE	AE	SE	ME	DE	AU	SU
8					BRXH	BRXLE	BXH	BXLE	SRL	SLL	SRA	SLA	SRDL	SLDL	SRDA	SLDA
9	STM	TM	MVI	TS	NI	CLI	OI	XI	LM		LAM	STAM
A									MVCLE	CLCLE						MC
B		LRA					STCTL	LCTL			CS	CDS		CLM	STCM	ICM
C
D		MVN	MVC	MVZ	NC	CLC	OC	XC		MVCK	MVCP	MVCS	TR	TRT	ED	EDMK
E		PKU	UNPKU						MVCIN	PKA	UNPKA				PLO	LMD
F	SRP	MVO	PACK	UNPK					ZAP	CP	AP	SP	MP	DP

Legend

Black without text

Not assigned / Not Shown

Green with black text

Move-type operations

Grey with red text

Store-type operations

Pink background

Bitwise operations:

Green text: Bitwise and operations
Black text: Bitwise or (inclusive) operations
Blue text: Bitwise exclusive-or operations

Red background

Algebraic operations:

Black text: Add operations
White text: Subtract operations
Blue text: Multiply operations
Yellow text: Divide operations
Green text: Halve operations

White background

Load-type operations:

Green text: Load positive operations
Black text: Load negative operations
Yellow text: Load and test operations
Blue text: Load complement operations
Red text: Load operations
Magenta text: Load-address operations

Yellow background

Compare-type operations:

Black text: Compare operations
Red text: Compare logical operations

Blue background

"Other" operations:

White text: Branching operations
Red text: Shifting operations
Black text: All remaining operations

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To the original instruction set.
To the horizontal stratification overview.
To the vertical stratification overview.

To the English Homepage.
To the general Homepage.

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