Z80 Machine Language Quick Guide (c) Mary Bell
Mary created this guide to the Z80 machine code and Assembly instruction set mostly for my own purposes while using a Z80 and the Radio Shack TRS-80’s, so thought it might be of use to others when learning or editing code. The guide consists of a series of tables not unlike the original Zilog Z80 Reference Manual, with signifigant changes to make the act of coding or decoding a program less clumbersome. The HTML versions are a little bit cluttered, so I recommend the graphical representations at the end of the page to be printed or followed for the construction of a 3×5 table for use by hand. Use of the tables themselves is un-restricted for non-commercial purposes.

Jumps & INCs 00 to 3F

1’s

16’s>

0

1

2

3

0

JR

NOP

DJNZ

NZ

NC

1

nn->

BC

DE

HL

SP

2

A->

(BC)

(DE)

(HL)

(nn)

3

INC

BC

DE

HL

SP

4

INC

B

D

H

(HL)

5

DEC

B

D

H

(HL)

6

n->

B

D

H

(HL)

7

 

RLCA

RLA

DAA

SCF

8

JR

AF<->AF’

UNC

Z

C

9

HL+

BC

DE

HL

SP

A

->A

(BC)

(DE)

(nn)->(HL)

(nn)

B

DEC

BC

DE

HL

SP

C

INC

C

E

L

A

D

DEC

C

E

L

A

E

n->

C

E

L

A

F

 

RRCA

RRA

CPL

CCF

1’s

16’s>

0

1

2

3

Call & Pushes C0 to FF

1’s

16’s>

C

D

E

F

0

RTN

NZ

NC

PO

NM

1

POP

BC

DE

HL

AF

2

JMP (nn)

NZ

NC

PO

NM

3

 

JMP (nn)

OUT (n)

HL<->(SP)

DIS INT

4

CALL (nn)

NZ

NC

PO

NM

5

PUSH

BC

DE

HL

AF

6

A/n

+

AND

OR

7

RST

00h

10h

20h

30h

8

RTN

Z

C

PE

M

9

 

RTN

EXX

JMP (HL)

HL->SP

A

JMP (nn)

Z

C

PE

M

B

 

CNTL BITS

IN (n)

HL<->DE

ENA INT

C

CALL (nn)

Z

C

PE

M

D

 

CALL (nn)

IX for HL

Ext Ins

IY for HL

E

A/n

+/cy

-/cy

XOR

CP

F

RST

08h

18h

28h

38h

1’s

16’s>

C

D

E

F

Extended Instructions ED+n

1’s

16’s>

4

5

6

7

A

B

0

IN(c)

B

D

H

 

LDI

LDIR

1

OUT(c)

B

D

H

 

CPI

CPIR

2

HL-/cy

BC

DE

HL

SP

INI

INIR

3

->(nn)

BC

DE

 

SP

OUTI

OUTIR

4

 

NEG

 

 

 

 

 

5

 

RET NMI

 

 

 

 

 

6

 

IM0

IM2

 

 

 

 

7

 

A->I

I->A

RRD

 

 

 

8

IN(c)

C

E

L

A

LDD

LDDR

9

OUT(c)

C

E

L

A

CPD

CPDR

A

HL+/cy

BC

DE

HL

SP

IND

INDR

B

(nn)->

BC

DE

HL

SP

OUTD

OUTDR

C

 

 

 

 

 

 

 

D

 

RET MI

 

 

 

 

 

E

 

 

IM2

 

 

 

 

F

 

A->R

R->A

RLD

 

 

 

1’s

16’s>

4

5

6

7

A

B

Register Ops 40 to 7F

source reg

operations w/A

B

C

D

E

H

L

(HL)

A

+/cy

-/cy

XOR

CP

C

E

L

A

8

9

A

B

C

D

E

F

<1’s

+

AND

OR

B

D

H

(HL)

0

1

2

3

4

5

6

7

<1’s

16’s>

8

9

A

B

4

5

6

7

Ex: 9A=SBC A,D

move destination

Note: 76=HALT

Control Bits CB+ 00-FF

Source Reg

Ex: CB 5A=TEST BIT 3,D

B

C

D

E

H

L

(HL)

A

BIT#

1’s>

8

9

A

B

C

D

E

F

1

3

5

7

RRC

RR

SRA

SRL

<ops

1’s>

0

1

2

3

4

5

6

7

0

2

4

6

RLC

RL

SLA

 

<ops

16’s>

SET>

C

D

E

F

0

1

2

3

<16’s

16’s>

RESET>

8

9

A

B

<16’s

16’s>

TEST>

4

5

6

7

<16’s

Graphics Version

In case you want to print this out full page and then cut it apart and paste to 3 by 5 cards for a home-made handy reference.

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