Exwrap RTS, Chksad PHP, Outxah PHA, Txa, Outbyt PHA

0427	8291	18				CLC
0428	8292	60			M29	RTS
0429	8293	EE 4A A6			INCP3	INC P3L		;INCREMENT P3 (16 BITS)
0430	8296	D0	03			BNE	*+5
0431	8298	EE 4B A6				INC	P3H
0432	829B	60				RTS
0433	829C	AE 4D A6			P2SCR	LDX P2H		;MOVE P2 TO FE,FF
0434	829F	86	FF			STX	$FF
0435	82A1	AE 4C A6				LDX	P2L
0436	82A4	86	FE			STX	$FE
0437	82A6	60				RTS
0438	82A7	AE 4B A6			P3SCR	LDX P3H		;MOVE P3 TO FE,FF
0439	82AA 86 FF					STX	$FF
0440	82AC AE 4A A6					LDX	P3L
0441	82AF 86 FE					STX	$FE
0442	82B1	60				RTS
0443	82B2	E6	FE		INCCMP INC $FE			;INCREM FE,FF, COMPARE TO P3
0444	82B4	D0	14			BNE	COMPAR
0445	82B6	E6	FF			INC	$FF
0446	82B8	D0	10		WRAP	BNE	COMPAR	;TEST TO WRAP AROUND
0447	82BA 2C BD 82					BIT	EXWRAP
0448	82BD 60				EXWRAP RTS
0449	82BE A5 FE				DECCMP LDA $FE			;DECREM FE,FF AND COMPARE TO P3
0450	82C0	D0	06			BNE	M32
0451	82C2	A5	FF			LDA	$FF
0452	82C4	F0	F2			BEQ	WRAP
0453	82C6	C6	FF			DEC	$FF
0454	82C8	C6	FE		M32	DEC	$FE
0455	82CA 20 88 81				COMPAR JSR		SAVER	;COMPARE FE,FF TO P3
0456	82CD A5 FF					LDA	$FF
0457	82CF CD 4B A6					CMP	P3H
0458	82D2	D0	05			BNE	EXITCP
0459	82D4	A5	FE			LDA	$FE
0460	82D6	CD 4A A6				CMP	P3L
0461	82D9	B8			EXITCP CLV
0462	82DA 4C BE 81					JMP	RESXF
0463	82DD 08				CHKSAD PHP			;16 BIT CKSUM IN SCR6,7
0464	82DE 48					PHA
0465	82DF 18					CLC
0466	82E0	6D	36	A6		ADC	SCR6
0467	82E3	8D	36	A6		STA	SCR6
0468	82E6	90	03			BCC	M33
0469	82E8	EE 37 A6				INC	SCR7
0470	82EB 68				M33	PLA
0471	82EC 28					PLP
0472	82ED 60					RTS
0473	82EE AD 59 A6				OUTPC	LDA PCLR		;OUTPUT PC
0474	82F1	AE 5A A6				LDX	PCHR
0475	82F4	48			OUTXAH PHA
0476	82F5	8A				TXA
0477	82F6	20	FA 82			JSR	OUTBYT
0478	82F9	68				PLA
0479	82FA 48				OUTBYT PHA			;OUTPUT 2 HEX DIGS FROM A
0480	82FB 48					PHA
0481	82FC 4A					LSR	A
0482	82FD 4A					LSR	A
0483	82FE 4A					LSR	A
0484	82FF 4A					LSR	A
0485	8300	20	44	8A		JSR	NBASOC
0486	8303	68				PLA
0487	8304	20	44	8A		JSR	NBASOC
0488	8307	68				PLA

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.

EXWRAP RTS

CMP

CMP

CHKSAD PHP

ADC

OUTXAH PHA

TXA

OUTBYT PHA

II specifications