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TOPIC -- Apple II -- Red Book Sweet-16 listing

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1

***********************

 

 

2

*

 

 

 

*

 

 

3

*

APPLE-II PSEUDO

*

 

 

4

* MACHINE INTERPRETER *

 

 

5

*

 

 

 

*

 

 

6

*

COPYRIGHT 1977

*

 

 

7

* APPLE COMPUTER INC

*

 

 

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*

 

 

 

*

 

 

9

* ALL RIGHTS RESERVED

*

 

 

10

*

S. WOZNIAK

*

 

 

11

*

 

 

 

*

 

 

12

***********************

 

 

13

 

 

 

 

 

; TITLE "SWEET16 INTERPRETER"

 

14

R0L

 

EQU

$0

 

 

 

15

R0H

 

EQU

$1

 

 

 

16

R14H

 

EQU

$1D

 

 

 

17

R15L

 

EQU

$1E

 

 

 

18

R15H

 

EQU

$1F

 

 

 

19

SW16PAG

EQU

$F7

 

 

 

20

SAVE

 

EQU

$FF4A

 

 

 

21

RESTORE

EQU

$FF3F

 

 

 

22

 

 

ORG

$F689

 

 

F689: 20 4A FF

23

SW16

 

JSR

SAVE

 

;PRESERVE 6502 REG CONTENTS

F68C: 68

24

 

 

PLA

 

 

 

F68D: 85 1E

25

 

 

STA

R15L

 

;INIT SWEET16 PC

F68F: 68

26

 

 

PLA

 

 

;FROM RETURN

F690: 85 1F

27

 

 

STA

R15H

 

; ADDRESS

F692: 20 98 F6

28

SW16B

JSR

SW16C

 

;INTERPRET AND EXECUTE

F695: 4C 92 F6

29

 

 

JMP

SW16B

 

;ONE SWEET16 INSTR.

F698: E6 1E

30

SW16C

INC

R15L

 

 

F69A: D0 02

31

 

 

BNE

SW16D

 

;INCR SWEET16 PC FOR FETCH

F69C: E6 1F

32

 

 

INC

R15H

 

 

F69E: A9 F7

33

SW16D

LDA

#SW16PAG

 

F6A0: 48

34

 

 

PHA

 

 

;PUSH ON STACK FOR RTS

F6A1: A0 00

35

 

 

LDY

#$0

 

 

F6A3: B1 1E

36

 

 

LDA

(R15L),Y

;FETCH INSTR

F6A5: 29 0F

37

 

 

AND

#$F

 

;MASK REG SPECIFICATION

F6A7: 0A

38

 

 

ASL

 

 

;DOUBLE FOR TWO BYTE REGISTERS

F6A8: AA

39

 

 

TAX

 

 

;TO X REG FOR INDEXING

F6A9: 4A

40

 

 

LSR

 

 

 

F6AA: 51 1E

41

 

 

EOR

(R15L),Y

;NOW HAVE OPCODE

F6AC: F0 0B

42

 

 

BEQ

TOBR

 

;IF ZERO THEN NON-REG OP

F6AE: 86 1D

43

 

 

STX

R14H

 

;INDICATE'PRIOR RESULT REG'

F6B0: 4A

44

 

 

LSR

 

 

 

F6B1: 4A

45

 

 

LSR

 

 

;OPCODE*2 TO LSB'S

F6B2: 4A

46

 

 

LSR

 

 

 

F6B3: A8

47

 

 

TAY

 

 

;TO Y REG FOR INDEXING

F6B4: B9 E1 F6

48

 

 

LDA

OPTBL-2,Y

;LOW ORDER ADR BYTE

F6B7: 48

49

 

 

PHA

 

 

;ONTO STACK

F6B8: 60

50

 

 

RTS

 

 

;GOTO REG-OP ROUTINE

F6B9: E6 1E

51

TOBR

 

INC

R15L

 

 

F6BB: D0 02

52

 

 

BNE

TOBR2

 

;INCR PC

F6BD: E6 1F

53

 

 

INC

R15H

 

 

F6BF: BD E4 F6

54

TOBR2

LDA

BRTBL,X

 

;LOW ORDER ADR BYTE

F6C2: 48

55

 

 

PHA

 

 

;ONTO STACK FOR NON-REG OP

F6C3: A5 1D

56

 

 

LDA

R14H

 

;'PRIOR RESULT REG' INDEX

 

 

 

 

 

 

 

 

Page 38 Page 40
Page 39
Image 39
Apple II manual Save, Brtbl,X
Page 38 Page 40

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.
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