3849

FD38 F0 0B

BEQ

FORMDS

 

3850

FD3A 88

DEY

 

 

3851

FD3B B8

CLV

 

 

3852

FD3C 50 F2

BVC STSHLP

;REPEAT TILL THRU

3853

FD3E

 

 

 

3854

FD3E A9 01

ONEBYT LDA #01

;SET BYTES = 1

3855

FD40 8D 2F A4

STA

BYTESM

 

3856

FD43 D0 E7

BNE

STASH

 

3857

FD45

 

 

 

3858

FD45

;FORMAT FOR SYSTEM 65 DISPLAY (REFORMAT FOR AIM)

3859

FD45 20 44 EB

FORMDS JSR

CLR

 

3860

FD48 20 DD E5

JSR

CGPC1

;ADDR TO SAVPC FOR DISASSEMBLY

3861

FD4B 20 42 E8

JSR

TTYTST

;IF TTY DO NOT GO TO DISASS

3862

FD4E D0 08

BNE

FORMD1

 

3863

FD50 20 3B E8

JSR

BLANK2

;IT IS TTY

3864

FD53 20 3B E8

JSR

BLANK2

 

3865

FD56 D0 11

BNE

FORMD2

;OUTPUT OPCODE

3866

FD58 20 6C F4

FORMD1 JSR

DISASM

 

3867

FD5B 20 24 EA

JSR

CRCK

;<CR> IF PRI PTR DIFF FROM 0

3868

FD5E AD 37 A4

LDA

CODFLG

;SEE IF HE WANTS CODE ALSO

3869

FD61 F0 1A

BEQ

FORM1

 

3870

FD63 20 3E E8

JSR

BLANK

 

3871

FD66 20 3C F5

JSR PRPC

;PROG CNTR

3872

FD69

;OUTPUT OPCODE

 

3873

FD69 AE 2F A4

FORMD2 LDX

BYTESM

 

3874

FD6C A0 00

LDY

#00

 

3875

FD6E A9 1C

DISPLY LDA

#ADDR

;DO LDA (ADDR),Y ,WHITOUT PAG 0

3876

FD70 20 58 EB

JSR

LDAY

 

3877

FD73 20 46 EA

JSR

NUMA

 

3878

FD76 20 3E E8

JSR

BLANK

 

3879

FD79 C8

INY

 

 

3880

FD7A CA

DEX

 

 

3881

FD7B D0 F1

BNE

DISPLY

 

3882

FD7D

 

 

 

3883

FD7D

;POINT TO NEXT INSTRUCTION LOCATION

3884

FD7D AC 2F A4

FORM1 LDY BYTESM

;ADD BYTESM TO ADDR

3885

FD80 20 CD E2

JSR

NXTADD

 

3886

FD83 4C 24 FF

JMP PATC16

;UPDATE PC

3887

FD86

 

 

 

3888

FD86

;RELATIVE BRANCH ADDRESS COMPUTATION

3889

FD86 AD 31 A4

BRCOMP LDA

TEMPX

 

3890

FD89 C9 02

CMP

#02

;IF REL BRANCH INPUT, USE IT

3891

FD8B D0 11

BNE

COMPBR

 

3892

FD8D A2 00

LDX

#00

 

3893

FD8F A0 01

LDY

#01

 

3894

FD91 20 12 FD

JSR

CONVRT

 

3895

FD94 B0 40

BCS

ERRJMP

 

3896

FD96 A9 02

LDA

#02

 

3897

FD98 8D 2F A4

STA

BYTESM

;SET PROPER BYTES

3898

FD9B 4C 2C FD

JMP

STASH

 

3899

FD9E A2 00

COMPBR LDX

#00

 

3900

FDA0 A0 02

LDY

#02

 

3901

FDA2 20 12 FD

JSR

CONVRT

 

3902

FDA5 B0 2F

BCS

ERRJMP

 

3903

FDA7 AD 1D A4

LDA

ADDR+1

;ADD BRANCH OFFSET

3904

FDAA 8D 27 01

STA

MOVAD+1

 

3905

FDAD AD 1C A4

LDA

ADDR

 

3906

FDB0 18

CLC

 

 

3907

FDB1 69 02

ADC

#02

 

3908

FDB3 8D 26 01

STA

MOVAD

 

3909

FDB6 90 03

BCC

CMPBR1

 

3910

FDB8 EE 27 01

INC

MOVAD+1

 

 

 

 

 

 

Page 204
Image 204
Apple II manual FORMD2 LDX, Brcomp LDA, Compbr LDX

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.