BCC RD3 Loop Until Done | Apple II instruction

FF24: 90 F0	1015		BCC	RD3	;LOOP UNTIL DONE
FF26: 20 EC FC	1016		JSR	RDBYTE	;READ CHKSUM BYTE
FF29: C5 2E	1017		CMP	CHKSUM
FF2B: F0 0D	1018		BEQ	BELL	;GOOD, SOUND BELL AND RETURN
FF2D: A9 C5	1019	PRERR	LDA	#$C5
FF2F: 20 ED FD	1020		JSR	COUT	;PRINT "ERR", THEN BELL
FF32: A9 D2	1021		LDA	#$D2
FF34: 20 ED FD	1022		JSR	COUT
FF37: 20 ED FD	1023		JSR	COUT
FF3A: A9 87	1024	BELL	LDA	#$87	;OUTPUT BELL AND RETURN
FF3C: 4C ED FD	1025		JMP	COUT
FF3F: A5 48	1026	RESTORE	LDA	STATUS	;RESTORE 6502 REG CONTENTS
FF41: 48	1027		PHA		;	USED BY DEBUG SOFTWARE
FF42: A5 45	1028		LDA	ACC
FF44: A6 46	1029	RESTR1	LDX	XREG
FF46: A4 47	1030		LDY	YREG
FF48: 28	1031		PLP
FF49: 60	1032		RTS
FF4A: 85 45	1033	SAVE	STA	ACC	;SAVE 6502 REG CONTENTS
FF4C: 86 46	1034	SAV1	STX	XREG
FF4E: 84 47	1035		STY	YREG
FF50: 08	1036		PHP
FF51: 68	1037		PLA
FF52: 85 48	1038		STA	STATUS
FF54: BA	1039		TSX
FF55: 86 49	1040		STX	SPNT
FF57: D8	1041		CLD
FF58: 60	1042		RTS
FF59: 20 84 FE	1043	RESET	JSR	SETNORM	;SET SCREEN MODE
FF5C: 20 2F FB	1044		JSR	INIT	;	AND INIT KBD/SCREEN
FF5F: 20 93 FE	1045		JSR	SETVID	;	AS I/O DEV'S
FF62: 20 89 FE	1046		JSR	SETKBD
FF65: D8	1047	MON	CLD		;MUST SET HEX MODE!
FF66: 20 3A FF	1048		JSR	BELL
FF69: A9 AA	1049	MONZ	LDA	#$AA	;'*' PROMPT FOR MON
FF6B: 85 33	1050		STA	PROMPT
FF6D: 20 67 FD	1051		JSR	GETLNZ	;READ A LINE
FF70: 20 C7 FF	1052		JSR	ZMODE	;CLEAR MON MODE, SCAN IDX
FF73: 20 A7 FF	1053	NXTITM	JSR	GETNUM	;GET ITEM, NON-HEX
FF76: 84 34	1054		STY	YSAV	;	CHAR IN A-REG
FF78: A0 17	1055		LDY	#$17	;	X-REG=0 IF NO HEX INPUT
FF7A: 88	1056	CHRSRCH	DEY
FF7B: 30 E8	1057		BMI	MON	;NOT FOUND, GO TO MON
FF7D: D9 CC FF	1058		CMP	CHRTBL,Y	;FIND CMND CHAR IN TEL
FF80: D0 F8	1059		BNE	CHRSRCH
FF82: 20 BE FF	1060		JSR	TOSUB	;FOUND, CALL CORRESPONDING
FF85: A4 34	1061		LDY	YSAV	;	SUBROUTINE
FF87: 4C 73 FF	1062		JMP	NXTITM
FF8A: A2 03	1063	DIG	LDX	#$03
FF8C: 0A	1064		ASL
FF8D: 0A	1065		ASL		;GOT HEX DIG,
FF8E: 0A	1066		ASL		;	SHIFT INTO A2
FF8F: 0A	1067		ASL
FF90: 0A	1068	NXTBIT	ASL
FF91: 26 3E	1069		ROL	A2L
FF93: 26 3F	1070		ROL	A2H
FF95: CA	1071		DEX		;LEAVE X=$FF IF DIG
FF96: 10 F8	1072		BPL	NXTBIT
FF98: A5 31	1073	NXTBAS	LDA	MODE
FF9A: D0 06	1074		BNE	NXTBS2	;IF MODE IS ZERO
FF9C: B5 3F	1075		LDA	A2H,X	; THEN COPY A2 TO
FF9E: 95 3D	1076		STA	A1H,X	; A1 AND A3

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.

BCC

RD3

;LOOP UNTIL DONE

II specifications