1357

8A2F D0 0B

 

 

BNE

INRT2

 

1358

8A31

AD 53 A6

 

LDA

TECHO

 

1359

8A34

49

40

 

 

EOR

#$40

;TOGGLE CTL O BIT

1360

8A36

8D

53

A6

 

STA

TECHO

 

1361

8A39

18

 

 

 

CLC

 

 

1362

8A3A 90 E2

 

 

BCC

INCHR+3

;GET GET ANOTHER CHAR

1363

8A3C C9 0D

 

INRT2

CMP

#$0D

;CARRIAGE RETURN?

1364

8A3E 4C B8 81

 

JMP

RESXAF

 

1365

8A41

6C

61

A6

INJINV JMP

(INVEC+1)

 

1366

8A44

20

09

83

NBASOC JSR

NIBASC

;NIBBLE TO ASCII, OUTCHR

1367

8A47

20

88

81

OUTCHR JSR

SAVER

 

1368

8A4A 2C 53 A6

 

BIT

TECHO

;LOOK AT CTRL O FLAG

1369

8A4D 70 03

 

 

BVS

*+5

 

1370

8A4F 20 55 8A

 

JSR

INJOUV

 

1371

8A52

4C

C4

81

 

JMP

RESALL

 

1372

8A55

6C

64

A6

INJOUV JMP

(OUTVEC+1)

 

1373

8A58

20

88

81

INTCHR JSR

SAVER

;IN TERMINAL CHAR

1374

8A5B A9 00

 

 

LDA

#0

 

1375

8A5D 85 F9

 

 

STA

$F9

 

1376

8A5F AD 02 A4

LOOK

LDA

PBDA

;FIND LEADING EDGE

1377

8A62

2D

54

A6

 

AND

TOUTFL

 

1378

8A65

38

 

 

 

SEC

 

 

1379

8A66

E9

40

 

 

SBC

#$40

 

1380

8A68

90

F5

 

 

BCC

LOOK

 

1381

8A6A 20 E9 8A

TIN

JSR

DLYH

;TERMINAL BIT

1382

8A6D AD 02 A4

 

LDA

PBDA

 

1383

8A70

2D

54

A6

 

AND

TOUTFL

 

1384

8A73

38

 

 

 

SEC

 

 

1385

8A74

E9

40

 

 

SBC #$40

;OR BITS 7,7 (TTY,CRT)

1386

8A76

2C

53

A6

 

BIT TECHO

;ECHO BIT?

1387

8A79

10

06

 

 

BPL

DMY1

 

1388

8A7B 20 D4 8A

 

JSR

OUT

 

1389

8A7E 4C 87 8A

 

JMP

SAVE

 

1390

8A81

A0

07

 

DMY1

LDY

#7

 

1391

8A83

88

 

 

TLP1

DEY

 

 

1392

8A84

D0

FD

 

 

BNE

TLP1

 

1393

8A86

EA

 

 

 

NOP

 

 

1394

8A87

66

F9

 

SAVE

ROR

$F9

 

1395

8A89

20

E9

8A

 

JSR

DLYH

 

1396

8A8C 48

 

 

 

PHA

 

;TIMING

1397

8A8D B5 00

 

 

LDA

0,X

 

1398

8A8F 68

 

 

 

PLA

 

 

1399

8A90

90

D8

 

 

BCC

TIN

 

1400

8A92

20

E9

8A

 

JSR

DLYH

 

1401

8A95

18

 

 

 

CLC

 

 

1402

8A96

20

D4

8A

 

JSR

OUT

 

1403

8A99

A5

F9

 

 

LDA

$F9

 

1404

8A9B 49 FF

 

 

EOR

#$FF

 

1405

8A9D 4C B8 81

 

JMP

RESXAF

 

1406

8AA0 85 F9

 

TOUT

STA

$F9

;TERMINAL CHR OUT

1407

8AA2 20 88 81

 

JSR

SAVER

 

1408

8AA5 20 E9 8A

 

JSR

DLYH

;DELAY 1/2 BIT TIME

1409

8AA8 A9 30

 

 

LDA

#$30

;SET FOR OUTPUT

1410

8AAA 8D 03 A4

 

STA

PBDA+1

;DATA DIRECTION

1411

8AAD A5 F9

 

 

LDA

$F9

;RECOVER CHR DATA

1412

8AAF A2 0B

 

 

LDX

#$0B

;START BIT,8DATA, 3STOPS

1413

8AB1 49 FF

 

 

EOR

#$FF

;INVERT DATA

1414

8AB3 38

 

 

 

SEC

 

;START BIT

1415

8AB4 20 D4 8A

OUTC

JSR

OUT

;OUTPUT BIT FROM CARRY

1416

8AB7 20 E6 8A

 

JSR

DLYF

;WAIT FULL BIT TIME

1417

8ABA A0 06

 

 

LDY

#$06

 

1418

8ABC 88

 

 

PHAKE

DEY

 

 

 

 

 

 

 

 

 

 

 

Page 124
Image 124
Apple II manual BNE INRT2

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.