0055

A659

 

 

PCLR

.BLOCK

1

;PROG CTR

0056

A65A

 

 

PCHR

.BLOCK

1

 

0057

A65B

 

 

SR

.BLOCK

1

;STACK

0058

A65C

 

 

FR

.BLOCK

1

;FLAGS

0059

A65D

 

 

AR

.BLOCK

1

;AREG

0060

A65E

 

 

XR

.BLOCK

1

;XREG

0061

A65F

 

 

YR

.BLOCK

1

;YREG

0062

A660

 

 

;

 

 

 

0063

A660

 

 

; I/O VECTORS

FOLLOW

 

0064

A660

 

 

;

 

 

 

0065

A660

 

 

INVEC

.BLOCK

3

;IN CHAR

0066

A663

 

 

OUTVEC

.BLOCK

3

;OUT CHAR

0067

A666

 

 

INSVEC

.BLOCK

3

;IN STATUS

0068

A669

 

 

URSVEC

.BLOCK

3

;UNRECOGNIZED SYNTAX VECTOR

0069

A66C

 

 

URCVEC

.BLOCK

3

;UNRECOGNIZED CMD/ERROR VECTOR

0070

A66F

 

 

SCNVEC .BLOCK

3

;SCAN ON-BOARD DISPLAY

0071

A672

 

 

;

 

 

 

0072

A672

 

 

; TRACE, INTERRUPT VECTORS

0073

A672

 

 

;

 

 

 

0074

A672

 

 

EXEVEC .BLOCK

2

; EXEC CMD ALTERNATE INVEC

0075

A674

 

 

TRCVEC .BLOCK

2

;TRACE

0076

A676

 

 

UBRKVC .BLOCK

2

;USER BRK AFTER MONITOR

0077

A678

 

 

UBRKV

=UBRKVC

 

 

0078

A678

 

 

UIRQVC

.BLOCK

2

;USER NON-BRK IRQ AFTER MONITOR

0079

A67A

 

 

UIRQV

=UIRQVC

 

 

0080

A67A

 

 

NMIVEC

.BLOCK

2

;NMI

0081

A67C

 

 

RSTVEC

.BLOCK

2

;RESET

0082

A67E

 

 

IRQVEC .BLOCK

2

;IRQ

0083

A680

 

 

;

 

 

 

0084

A680

 

 

;

 

 

 

0085

A680

 

 

;I/O REG DEFINITIONS

 

0086

A680

 

 

PADA

=$A400

 

;KEYBOARD/DISPLAY

0087

A680

 

 

PBDA

=$A402

 

;SERIAL I/O

0088

A680

 

 

OR3A

=$AC01

 

;WP, DBON, DBOFF

0089

A680

 

 

DDR3A

=OR3A+2

 

;DATA DIRECTION FOR SAME

0090

A680

 

 

OR1B

=$A000

 

 

0091

A680

 

 

DDR1B

=$A002

 

 

0092

A680

 

 

PCR1

=$A00C

 

; POR/TAPE REMOTE

0093

A680

 

 

;

 

 

 

0094

A680

 

 

; MONITOR MAINLINE

 

0095

A680

 

 

;

 

 

 

0096

8000

 

 

 

*=$8000

 

 

0097

8000

4C

7C 8B

MONITR JMP MONENT

;INIT S, CLD, GET ACCESS

0098

8003

20

FF 80

WARM

JSR GETCOM

;GET COMMAND + PARMS (0-3)

0099

8006

20

4A 81

 

JSR DISPAT

;DISPATCH CMD,PARMS TO EXEC BLKS

0100

8009

20

71 81

 

JSR ERMSG

;DISP ER MSG IF CARRY SET

0101

800C

4C

03 80

 

JMP WARM

;AND CONTINUE

0102

800F

 

 

;

 

 

 

0103

800F

 

 

; TRACE AND INTERRUPT ROUTINES

0104

800F

 

 

;

 

 

 

0105

800F

08

 

IRQBRK PHP

 

;IRQ OR BRK ?

0106

8010

48

 

 

PHA

 

 

0107

8011

8A

 

 

TXA

 

 

0108

8012

48

 

 

PHA

 

 

0109

8013

BA

 

 

TSX

 

 

0110

8014

BD 04 01

 

LDA $0104,X

;PICK UP FLAGS

0111

8017

29

10

 

AND #$10

 

0112

8019

F0

07

 

BEQ DETIRQ

 

0113

801B

68

 

 

PLA

 

;BRK

0114

801C

AA

 

 

TAX

 

 

0115

801D

68

 

 

PLA

 

 

0116

801E

28

 

 

PLP

 

 

 

 

 

 

 

 

 

 

Page 103
Image 103
Apple II manual Outvec, Urcvec, =Ubrkvc, =Uirqvc, Nmivec

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.