BCC Clreol Clear to END of Line

FC3E: 90 5C	643		BCC	CLREOL	;	E, CLEAR TO END OF LINE
FC40: D0 E9	644		BNE	RTS4	;	NOT F, RETURN
FC42: A4 24	645	CLREOP	LDY	CH	;CURSOR H TO Y INDEX
FC44: A5 25	646		LDA	CV	;CURSOR V TO A-REGISTER
FC46: 48	647	CLEOP1	PHA		;SAVE CURRENT LINE ON STK
FC47: 20 24 FC	648		JSR	VTABZ	;CALC BASE ADDRESS
FC4A: 20 9E FC	649		JSR	CLEOLZ	;CLEAR TO EOL, SET CARRY
FC4D: A0 00	650		LDY	#$00	;CLEAR FROM H INDEX=0 FOR REST
FC4F: 68	651		PLA		;INCREMENT CURRENT LINE
FC50: 69 00	652		ADC	#$00	;(CARRY IS SET)
FC52: C5 23	653		CMP	WNDBTM	;DONE TO BOTTOM OF WINDOW?
FC54: 90 F0	654		BCC	CLEOP1	;	NO, KEEP CLEARING LINES
FC56: B0 CA	655		BCS	VTAB	;	YES, TAB TO CURRENT LINE
FC58: A5 22	656	HOME	LDA	WNDTOP	;INIT CURSOR V
FC5A: 85 25	657		STA	CV	;	AND H-INDICES
FC5C: A0 00	658		LDY	#$00
FC5E: 84 24	659		STY	CH	;THEN CLEAR TO END OF PAGE
FC60: F0 E4	660		BEQ	CLEOP1
FC62: A9 00	661	CR	LDA	#$00	;CURSOR TO LEFT OF INDEX
FC64: 85 24	662		STA	CH	;(RET CURSOR H=0)
FC66: E6 25	663	LF	INC	CV	;INCR CURSOR V(DOWN 1 LINE)
FC68: A5 25	664		LDA	CV
FC6A: C5 23	665		CMP	WNDBTM	;OFF SCREEN?
FC6C: 90 B6	666		BCC	VTABZ	;	NO, SET BASE ADDR
FC6E: C6 25	667		DEC	CV	;DECR CURSOR V (BACK TO BOTTOM)
FC70: A5 22	668	SCROLL	LDA	WNDTOP	;START AT TOP OF SCRL WNDW
FC72: 48	669		PHA
FC73: 20 24 FC	670		JSR	VTABZ	;GENERATE BASE ADR
FC76: A5 28	671	SCRL1	LDA	BASL	;COPY BASL,H
FC78: 85 2A	672		STA	BAS2L	;	TO BAS2L,H
FC7A: A5 29	673		LDA	BASH
FC7C: 85 2B	674		STA	BAS2H
FC7E: A4 21	675		LDY	WNDWDTH	;INIT Y TO RIGHTMOST INDEX
FC80: 88	676		DEY		;	OF SCROLLING WINDOW
FC81: 68	677		PLA
FC82: 69 01	678		ADC	#$01	;INCR LINE NUMBER
FC84: C5 23	679		CMP	WNDBTM	;DONE?
FC86: B0 0D	680		BCS	SCRL3	;	YES, FINISH
FC88: 48	681		PHA
FC89: 20 24 FC	682		JSR	VTABZ	;FORM BASL,H (BASE ADDR)
FC8C: B1 28	683	SCRL2	LDA	(BASL),Y	;MOVE A CHR UP ON LINE
FC8E: 91 2A	684		STA	(BAS2L),Y
FC90: 88	685		DEY		;NEXT CHAR OF LINE
FC91: 10 F9	686		BPL	SCRL2
FC93: 30 E1	687		BMI	SCRL1	;NEXT LINE (ALWAYS TAKEN)
FC95: A0 00	688	SCRL3	LDY	#$00	;CLEAR BOTTOM LINE
FC97: 20 9E FC	689		JSR	CLEOLZ	;GET BASE ADDR FOR BOTTOM LINE
FC9A: B0 86	690		BCS	VTAB	;CARRY IS SET
FC9C: A4 24	691	CLREOL	LDY	CH	;CURSOR H INDEX
FC9E: A9 A0	692	CLEOLZ	LDA	#$A0
FCA0: 91 28	693	CLEOL2	STA	(BASL),Y	;STORE BLANKS FROM 'HERE'
FCA2: C8	694		INY		;	TO END OF LINES (WNDWDTH)
FCA3: C4 21	695		CPY	WNDWDTH
FCA5: 90 F9	696		BCC	CLEOL2
FCA7: 60	697		RTS
FCA8: 38	698	WAIT	SEC
FCA9: 48	699	WAIT2	PHA
FCAA: E9 01	700	WAIT3	SBC	#$01
FCAC: D0 FC	701		BNE	WAIT3	;1.0204 USEC
FCAE: 68	702		PLA		;(13+27/2A+5/2A*A)
FCAF: E9 01	703		SBC	#$01
FCB1: D0 F6	704		BNE	WAIT2

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

CLREOL

E, CLEAR TO END OF LINE

II specifications