Apple II manual JSR Brtt INC Ercnt UP to FF

Models: II

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Page 118
Image 118

0985

872B

20

C1

87

 

JSR BRTT

;INC ERCNT (UP TO FF)

0986

872E

20

B2

82

F3

JSR INCCMP

 

0987

8731

70

7C

 

 

BVS B1

 

0988

8733

F0

EE

 

 

BEQ F1

 

0989

8735

90

EC

 

 

BCC F1

 

0990

8737

B0

76

 

F2

BCS B1

;(ALWAYS)

0991

8739

C9

42

 

BLK3

CMP #'B'

;BLOCK MOVE (OVERLAP OKAY)

0992

873B

F0

03

 

 

BEQ *+5

 

0993

873D

4C

CD 87

 

JMP S13B

 

0994

8740

A9

00

 

 

LDA #0

 

0995

8742

8D

52

A6

 

STA ERCNT

 

0996

8745

20

9C

82

 

JSR P2SCR

 

0997

8748

AD 4E A6

 

LDA P1L

 

0998

874B

85

FC

 

 

STA $FC

 

0999

874D

AD 4F A6

 

LDA P1H

 

1000

8750

85

FD

 

 

STA $FD

 

1001

8752

C5

FF

 

 

CMP $FF

;WHICH DIRECTION TO MOVE?

1002

8754

D0

06

 

 

BNE *+8

 

1003

8756

A5

FC

 

 

LDA $FC

 

1004

8758

C5

FE

 

 

CMP $FE

 

1005

875A

F0

53

 

 

BEQ B1

;16 BITS EQUAL THEN FINISHED

1006

875C

B0

14

 

 

BCS B2

;MOVE DEC'NG

1007

875E

20

B7

87

BLP

JSR BMOVE

;MOVE INC'NG

1008

8761

E6

FC

 

 

INC $FC

 

1009

8763

D0

02

 

 

BNE *+4

 

1010

8765

E6

FD

 

 

INC $FD

 

1011

8767

20

B2

82

 

JSR INCCMP

 

1012

876A

70

43

 

 

BVS B1

 

1013

876C

F0

F0

 

 

BEQ BLP

 

1014

876E

90

EE

 

 

BCC BLP

 

1015

8770

B0

3D

 

 

BCS B1

 

1016

8772

A5

FC

 

B2

LDA $FC

;CALC VALS FOR MOVE DEC'NG

1017

8774

18

 

 

 

CLC

 

1018

8775

6D

4A

A6

 

ADC P3L

 

1019

8778

85

FC

 

 

STA $FC

 

1020

877A

A5

FD

 

 

LDA $FD

 

1021

877C

6D

4B

A6

 

ADC P3H

 

1022

877F

85

FD

 

 

STA $FD

 

1023

8781

38

 

 

 

SEC

 

1024

8782

A5

FC

 

 

LDA $FC

 

1025

8784

E5

FE

 

 

SBC $FE

 

1026

8786

85

FC

 

 

STA $FC

 

1027

8788

A5

FD

 

 

LDA $FD

 

1028

878A

E5

FF

 

 

SBC $FF

 

1029

878C

85

FD

 

 

STA $FD

 

1030

878E

20

A7

82

 

JSR P3SCR

 

1031

8791

AD 4C A6

 

LDA P2L

 

1032

8794

8D

4A

A6

 

STA P3L

 

1033

8797

AD 4D A6

 

LDA P2H

 

1034

879A

8D

4B

A6

 

STA P3H

 

1035

879D

20

B7

87

BLP1

JSR BMOVE

;MOVE DEC'NG

1036

87A0

A5

FC

 

 

LDA $FC

 

1037

87A2

D0

02

 

 

BNE *+4

 

1038

87A4

C6

FD

 

 

DEC $FD

 

1039

87A6

C6

FC

 

 

DEC $FC

 

1040

87A8

20

BE 82

 

JSR DECCMP

 

1041

87AB 70 02

 

 

BVS B1

 

1042

87AD B0 EE

 

 

BCS BLP1

 

1043

87AF AD 52 A6

B1

LDA ERCNT

;FINISHED, TEST ERCNT

1044

87B2

38

 

 

 

SEC

 

1045

87B3

D0

01

 

 

BNE *+3

 

1046

87B5

18

 

 

 

CLC

 

 

 

 

 

 

 

 

 

Page 118
Image 118
Apple II manual JSR Brtt INC Ercnt UP to FF