1791

8C8E 85

FD

 

 

STA

MODE

 

1792

8C90

20

26

8E

 

JSR

RDBYTX

;READ ID BYTE ON TAPE

1793

8C93

8D

00

A4

 

STA

DIG

;DISPLAY ON LED (NOT DECODED)

1794

8C96

CD

4E

A6

 

CMP

ID

;COMPARE WITH REQUESTED ID

1795

8C99

F0

29

 

 

BEQ

LOADT5

;LOAD IF EQUAL

1796

8C9B AD

4E

A6

 

LDA

ID

;COMPARE WITH 0

1797

8C9E C9

00

 

 

CMP

#0

 

1798

8CA0 F0

22

 

 

BEQ

LOADT5

;IF 0, LOAD ANYWAY

1799

8CA2 C9

FF

 

 

CMP

#$FF

;COMPARE WITH FF

1800

8CA4 F0

07

 

 

BEQ LOADT6

;IF FF, USE REQUEST SA TO LOAD

1801

8CA6

 

 

 

 

 

 

 

1802

8CA6 24

FD

 

 

BIT MODE

;UNWANTED RECORD, KIM OR HS?

1803

8CA8 30

16

 

 

BMI

HWRONG

 

1804

8CAA 4C

7B

8C

 

JMP LOADT2

;IF KIM, RESTART SEARCH

1805

8CAD

 

 

 

 

 

 

 

1806

8CAD

 

 

 

; SA (&EA IF USED) COME FROM REQUEST. DISCARD TAPE VALUES

1807

8CAD

 

 

 

; (BUFAD

ALREADY SET TO SA BY 'START')

1808

8CAD

 

 

 

;

 

 

 

1809

8CAD 20

74

8E

LOADT6 JSR RDCHK

;GET SAL FROM TAPE

1810

8CB0 20

74

8E

 

JSR RDCHK

;GET SAH FROM TAPE

1811

8CB3 24

FD

 

 

BIT MODE

;HS OR KIM?

1812

8CB5 10

52

 

 

BPL LOADT7

;IF KIM, START READING DATA

1813

8CB7 20

74

8E

 

JSR RDCHK

;HS, GET EAH, EAL FROM TAPE

1814

8CBA 20

74

8E

 

JSR RDCHK

; ... BUT IGNORE

1815

8CBD 4C

DE 8C

 

JMP LT7H

;START READING HS DATA

1816

8CC0

 

 

 

 

 

 

 

1817

8CC0

 

 

 

; SA ( & EA IF USED) COME FROM TAPE. SA REPLACES BUFAD

1818

8CC0

 

 

 

 

 

 

 

1819

8CC0 A9

C0

 

HWRONG LDA #$C0

;READ THRU TO GE TO NEXT REC

1820

8CC2 85

FD

 

 

STA MODE

;BUT DON'T CHECK CKSUM, NO FRAME ERR

1821

8CC4

 

 

 

 

 

 

 

1822

8CC4 20

74

8E

LOADT5 JSR RDCHK

;GET SAL FROM TAPE

1823

8CC7 85

FE

 

 

STA BUFADL

;PUT IN BUF START L

1824

8CC9 20

74

8E

 

JSR RDCHK

;SAME FOR SAH

1825

8CCC 85

FF

 

 

STA

BUFADH

 

1826

8CCE

 

 

 

;(SAL - H STILL HAVE REQUEST VALUE)

1827

8CCE 24

FD

 

 

BIT MODE

;HS OR KIM?

1828

8CD0 10

37

 

 

BPL LOADT7

;IF KIM, START READING RECORD

1829

8CD2 20

74

8E

 

JSR RDCHK

;HS. GET & SAVE EAL,EAH

1830

8CD5 8D

4A

A6

 

STA

EAL

 

1831

8CD8 20

74

8E

 

JSR

RDCHK

 

1832

8CDB 8D

4B

A6

 

STA

EAH

 

1833

8CDE

 

 

 

 

 

 

 

1834

8CDE

 

 

 

; READ HS DATA

 

1835

8CDE

 

 

 

 

 

 

 

1836

8CDE 20

E5

8D

LT7H

JSR RDBYTH

;GET NEXT BYTE

1837

8CE1 A6

FE

 

 

LDX BUFADL

;CHECK FOR END OF DATA + 1

1838

8CE3 EC

4A

A6

 

CPX

EAL

 

1839

8CE6 D0

07

 

 

BNE

LT7HA

 

1840

8CE8 A6

FF

 

 

LDX

BUFADH

 

1841

8CEA EC

4B

A6

 

CPX

EAH

 

1842

8CED F0

14

 

 

BEQ

LT7HB

 

1843

8CEF 20

77

8E

LT7HA

JSR

CHKT

;NOT END, UPDATE CHECKSUM

1844

8CF2 24

FD

 

 

BIT

MODE

;WRONG RECORD?

1845

8CF4 70

04

 

 

BVS

LT7HC

;IF SO, DONT STORE BYTE

1846

8CF6 A0

00

 

 

LDY

#0

;STORE BYTE

1847

8CF8 91

FE

 

 

STA

(BUFADL),Y

 

1848

8CFA E6

FE

 

LT7HC

INC

BUFADL

;BUMP BUFFER ADDR

1849

8CFC D0

E0

 

 

BNE

LT7H

 

1850

8CFE E6

FF

 

 

INC

BUFADH

;CARRY

1851

8D00

4C

DE 8C

 

JMP

LT7H

 

1852

8D03

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Page 131
Image 131
Apple II manual STA Mode

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.