0976

E5E9 60

 

 

 

RTS

 

0977

E5EA

 

 

 

 

 

 

0978

E5EA

 

 

 

;***** P COMMAND-ALTER PROCESSOR STATUS *****

0979

E5EA A2 00

 

CGPS

LDX #0

 

0980

E5EC F0 0E

 

 

BEQ CGALL

 

0981

E5EE

 

 

 

 

 

 

0982

E5EE

 

 

 

;***** A COMMAND-ALTER ACCUMULATOR *****

0983

E5EE A2 01

 

CGA

LDX #1

 

0984

E5F0 D0 0A

 

 

BNE CGALL

 

0985

E5F2

 

 

 

 

 

 

0986

E5F2

 

 

 

;***** X COMMAND-ALTER X REGISTER *****

0987

E5F2 A2 02

 

CGX

LDX #2

 

0988

E5F4 D0 06

 

 

BNE CGALL

 

0989

E5F6

 

 

 

 

 

 

0990

E5F6

 

 

 

;***** Y COMMAND-ALTER Y REGISTER *****

0991

E5F6 A2 03

 

CGY

LDX #3

 

0992

E5F8 D0 02

 

 

BNE CGALL

 

0993

E5FA

 

 

 

 

 

 

0994

E5FA

 

 

 

;***** S COMMAND-ALTER STACK POINTER *****

0995

E5FA A2 04

 

CGS

LDX #4

 

0996

E5FC 20 D8 E7

CGALL

JSR EQUAL

;PRINT PROMPT

0997

E5FF 20 5D EA

 

JSR RD2

;GET VALUE FROM KEYBOARD

0998

E602

B0

04

 

 

BCS GOERR

 

0999

E604

9D

20

A4

 

STA SAVPS,X

 

1000

E607

60

 

 

 

RTS

 

1001

E608

20

D4

E7

GOERR

JSR QM

 

1002

E60B D0 EF

 

 

BNE CGALL

 

1003

E60D

 

 

 

 

 

 

1004

E60D

 

 

 

;***** <SPACE> COMMAND-SHOW NEXT 5 MEMORY LOC *****

1005

E60D 20 3E E8

NXT5

JSR BLANK

 

1006

E610

A0

04

 

 

LDY #4

;UPDATE ADDR FROM

1007

E612

20

CD E2

 

JSR NXTADD

;<M>=XXXX

1008

E615

20

DB E2

 

JSR WRITAZ

;OUTPUT ADDRESS

1009

E618

4C

4D

E2

 

JMP MEIN

;DISPLAY CONTENTS OF NEXT 4 LOCS

1010

E61B

 

 

 

 

 

 

1011

E61B

 

 

 

;***** B COMMAND-SET BREAKPOINT ADDR *****

1012

E61B A0 27

 

BRKA

LDY #M8-M1

;PRINT "BRK"

1013

E61D 20 AF E7

 

JSR KEP

 

1014

E620

20

37

E8

BRK1

JSR PSL1

;PRINT "/"

1015

E623

20

73

E9

 

JSR REDOUT

;GET BREAK NUMBER

1016

E626

38

 

 

 

SEC

 

1017

E627

E9

30

 

 

SBC #'0'

;0 THRU 3

1018

E629

30

04

 

 

BMI BKERR

;CHARACTER < '0' -ILLEGAL

1019

E62B C9 04

 

 

CMP #4

;FOUR BRK POINTS

1020

E62D 30 05

 

 

BMI BKOK

;0 < CHARACTER < 4 -OK

1021

E62F 20 D4 E7

BKERR

JSR QM

;ERROR

1022

E632

D0

EC

 

 

BNE BRK1

;ALLOW REENTRY OF BREAK NUMBER

1023

E634

0A

 

 

BKOK

ASL A

;*2 TO FORM WORD OFFSET

1024

E635

48

 

 

 

PHA

;SAVE IT

1025

E636

20

AE EA

 

JSR ADDIN

;GET ADDRESS FOR BREAKPOINT

1026

E639

68

 

 

 

PLA

 

1027

E63A B0 10

 

 

BCS BKO2

;BAD ADDRESS ENTERED

1028

E63C 20 3D FF

 

JSR PATC18

;<CR> & CLR BUFFERS

1029

E63F AA

 

 

 

TAX

;# OF BRK

1030

E640

AD 1C A4

 

LDA ADDR

;STORE ENTERED ADDR IN BRKPT LIST

1031

E643

9D

00

01

 

STA BKS,X

 

1032

E646

AD 1D A4

 

LDA ADDR+1

 

1033

E649

9D

01

01

 

STA BKS+1,X

 

1034

E64C 60

 

 

BKO2

RTS

;ALL DONE

1035

E64D

 

 

 

 

 

 

1036

E64D

 

 

 

;***** ? COMMAND-SHOW CURRENT BREAKPOINTS *****

1037

E64D A0 00

 

SHOW

LDY #0

 

 

 

 

 

 

 

 

 

Page 156
Image 156
Apple II manual E5EA

II specifications

The Apple II, launched in April 1977, was one of the first highly successful mass-produced microcomputer products. It marked a significant leap in personal computing, setting standards for future developments in the industry. Created by Steve Wozniak and Steve Jobs, the Apple II differentiated itself with its user-friendly design, appealing aesthetics, and robust capabilities.

One of the standout features of the Apple II was its open architecture, which allowed users to expand and enhance the computer's functionality. This design enabled hundreds of third-party hardware and software developers to contribute to its ecosystem, resulting in an array of peripherals, including printers, modems, and storage devices. The Apple II utilized a MOS Technology 6502 microprocessor running at a clock speed of 1 MHz. Initially equipped with 4 KB of RAM, the machine could be expanded to 48 KB, accommodating more complex applications and programs.

The Apple II was also notable for its colorful graphics. It was one of the first computers to support color display, offering a 6-color palette with a resolution of 280x192 pixels in 16 colors when using its Color Graphics Card. This feature significantly enhanced the visual appeal of games and educational software developed for the platform, making computing more accessible and entertaining for various audiences.

Apple's commitment to user experience was evident in the design of the machine. It featured an integrated keyboard and a plastic case, which was both durable and visually appealing. The self-contained design included drive bays for floppy disk drives, allowing for quicker data access than traditional tape drives. It also supported audio output, enabling sound effects and music, a novelty at the time.

The introduction of the Apple DOS operating system further underscored the machine's capabilities. DOS streamlined file management and made it easier for users to navigate and manage their data. The combination of hardware and software positioned the Apple II as an educational tool and a gaming platform, fostering a vibrant software ecosystem.

The Apple II family continued to evolve, with variations like the Apple II+, IIe, and IIgs being introduced over the years. These iterations brought enhancements in memory, processing power, and graphics capabilities. The legacy of the Apple II endures, not only as a foundational product in personal computing but also as a symbol of innovation that paved the way for future advancements in technology. Its impact is still felt today, as it inspired countless developers and shaped the trajectory of the computer industry.