2709

F24A

 

 

 

;OUTPUT ACC TO TAPE

 

2710

F24A 8E

2D

A4

OUTTAP STX CPIY+3

;SAVE X

2711

F24D A0

07

 

 

LDY #$07

;FOR THE 8 BITS

2712

F24F 8C

27

A4

 

STY

STIY

 

2713

F252

AE

08

A4

 

LDX

TSPEED

 

2714

F255

30

39

 

 

BMI OUTTA1

;IF ONE IS SUPER HIPER

2715

F257

48

 

 

 

PHA

 

 

2716

F258

A0

02

 

TRY

LDY

#2

;SEND 3 UNITS

2717

F25A 8C

28

A4

 

STY

STIY+1

;STARTING AT 3700 HZ

2718

F25D BE

0A

A4

ZON

LDX NPUL,Y

;#OF HALF CYCLES

2719

F260

48

 

 

 

PHA

 

 

2720

F261

B9

0B

A4

ZON1

LDA TIMG,Y

;SET UP LACTH FOR NEXT

2721

F264

8D

06

A8

 

STA T1LL

;PULSE (80 OR CA) (FREC)

2722

F267

A9

00

 

 

LDA

#0

 

2723

F269

8D

07

A8

 

STA

T1LH

 

2724

F26C 2C

0D

A8

ZON2

BIT

IFR

;WAIT FOR PREVIOUS

2725

F26F 50

FB

 

 

BVC

ZON2

;CYCLE (T1 INT FLG)

2726

F271

AD

04

A8

 

LDA T1L

;CLR INTERR FLG

2727

F274

CA

 

 

 

DEX

 

 

2728

F275

D0

EA

 

 

BNE ZON1

;SEND ALL CYCLES

2729

F277

68

 

 

 

PLA

 

 

2730

F278

CE

28

A4

 

DEC

STIY+1

 

2731

F27B F0

05

 

 

BEQ

SETZ

;BRCH IF LAST ONE

2732

F27D 30

07

 

 

BMI

ROUT

;BRCH IF NO MORE

2733

F27F 4A

 

 

 

LSR

A

;TAKE NEXT BIT

2734

F280

90

DB

 

 

BCC

ZON

;...IF IT'S A ONE...

2735

F282

A0

00

 

SETZ

LDY

#0

;SWITCH TO 2400 HZ

2736

F284

F0

D7

 

 

BEQ

ZON

;UNCONDITIONAL BRCH

2737

F286

CE

27

A4

ROUT

DEC

STIY

;ONE LESS BIT

2738

F289

10

CD

 

 

BPL TRY

;ANY MORE? GO BACK

2739

F28B 68

 

 

ROUT1

PLA

 

;RECOVER CHR

2740

F28C AE

2D

A4

 

LDX CPIY+3

;RESTORE X

2741

F28F 60

 

 

 

RTS

 

 

2742

F290

 

 

 

 

 

 

 

2743

F290

 

 

 

;OUTPUT HALF PULSE FOR

0 (1200 HZ) &

2744

F290

 

 

 

;TWO HALF PULSES FOR 1

(2400 HZ) (00 TSPEED)

2745

F290

48

 

 

OUTTA1 PHA

 

 

2746

F291

8D

28

A4

 

STA STIY+1

;STORE ACC

2747

F294

A2

02

 

OUTTA2 LDX

#2

;# OF HALF PULSES

2748

F296

A9

D0

 

 

LDA

#$D0

;1/2 PULSE OF 2400

2749

F298

8D

06

A8

 

STA

T1LL

 

2750

F29B A9

00

 

 

LDA

#00

 

2751

F29D 8D

07

A8

 

STA

T1LH

 

2752

F2A0 20

BC FF

 

JSR

PATC25

;WAIT TILL COMPLETED

2753

F2A3 4E

28

A4

 

LSR

STIY+1

;GET BITS FROM CHR

2754

F2A6 B0

0A

 

 

BCS

OUTTA3

 

2755

F2A8 A9

A0

 

 

LDA

#$A0

;BIT=0 ,OUTPUT 1200 HZ

2756

F2AA 8D

06

A8

 

STA

T1LL

 

2757

F2AD A9

01

 

 

LDA

#$01

 

2758

F2AF 8D

07

A8

 

STA

T1LH

 

2759

F2B2 20

BC FF

OUTTA3 JSR

PATC25

 

2760

F2B5 CA

 

 

 

DEX

 

 

2761

F2B6 10

FA

 

 

BPL OUTTA3

;OUTPUT 3 HALF PULSES

2762

F2B8 88

 

 

 

DEY

 

 

2763

F2B9 10

D9

 

 

BPL OUTTA2

;ALL BITS ?

2764

F2BB 4C

8B

F2

 

JMP ROUT1

;RESTORE REGS

2765

F2BE EA

 

 

 

NOP

 

 

2766

F2BF EA

 

 

 

NOP

 

 

2767

F2C0

 

 

 

 

 

 

 

2768

F2C0

 

 

 

;SET SPEED FROM NORMAL TO 3 TIMES NORMAL

2769

F2C0 AD

08

A4

SETSPD LDA TSPEED

;SPEED FLG

2770

F2C3 6A

 

 

 

ROR A

;NORMAL OR 3* NORM

 

 

 

 

 

 

 

 

 

Page 184
Image 184
Apple II manual OUTTA1 PHA, OUTTA2 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.