RS6 JSR Crlow Clear Display | Apple II specification

0425	E13E 20 13 EA				RS6	JSR	CRLOW	;CLEAR DISPLAY
0426	E141	4C	72	FF		JMP	PAT21
0427	E144	A2	13		RS7	LDX #19		;CLEAR HARDWARE CURSORS
0428	E146	8A			RS8	TXA
0429	E147	48				PHA
0430	E148	A9	00			LDA	#0
0431	E14A 20 7B EF					JSR	OUTDD1
0432	E14D 68					PLA
0433	E14E AA					TAX
0434	E14F CA					DEX
0435	E150	10	F4			BPL	RS8
0436	E152	30	EA			BMI	RS6
0437	E154
0438	E154				;BRK INSTR		(00) OR IRQ ENTRY POINT
0439	E154	8D	21	A4	IRQV3	STA	SAVA
0440	E157	68				PLA
0441	E158	48				PHA		;GET STATUS
0442	E159	29	10			AND	#$10	;SEE IF 'BRK' , ISOLATE B FLG
0443	E15B D0 06					BNE	IRQ1	;TRAP WAS CAUSED BY "BRK" INSTRUC
0444	E15D AD 21 A4					LDA	SAVA	;TRAP CAUSED BY IRQ SO TRANSFER
0445	E160	6C	00	A4		JMP	(MONRAM)	;CONTROL TO USER THRU VECTOR
0446	E163				;IS 'BRK' INSTR ,SHOW PC & DATA
0447	E163				;PC IS OFF BY ONE , SO ADJUST IT
0448	E163	68			IRQ1	PLA
0449	E164	8D	20	A4		STA SAVPS		;SAVE PROCESSOR STATUS
0450	E167	8E	22	A4		STX	SAVX
0451	E16A 8C 23 A4					STY	SAVY
0452	E16D D8					CLD
0453	E16E 68					PLA		;PROGR CNTR
0454	E16F 38					SEC		;SUBTRACT ONE FROM RETURN ADDR
0455	E170	E9	01			SBC	#1
0456	E172	8D	25	A4		STA	SAVPC
0457	E175	68				PLA
0458	E176	E9	00			SBC	#0
0459	E178	8D	26	A4		STA	SAVPC+1
0460	E17B BA					TSX		;GET STACK PTR & SAVE IT
0461	E17C 8E 24 A4					STX	SAVS
0462	E17F				;SHOW PC AND DATA
0463	E17F 20 61 F4				IRQ2	JSR REGQ		;SHOW NEXT INSTRUCTION & CONTINUE
0464	E182
0465	E182				;THIS ROUTINE WILL GET A CHR WITH "( )" FROM
0466	E182				;KB/TTY & THEN WILL GO TO THE RESPECTIVE COMMAND
0467	E182	4C	59	FF	START	JMP PAT19		;CLEAR DEC MODE & <CR>
0468	E185	A9	BC		STA1	LDA #'<'+$80		;"<" CHR WITH MSB=1 FOR DISP
0469	E187	20	7A	E9		JSR	OUTPUT
0470	E18A 20 96 FE					JSR RED1		;GET CHR & ECHO FROM KB/TTY
0471	E18D 48					PHA
0472	E18E A9 3E					LDA	#'>'
0473	E190	20	7A	E9		JSR	OUTPUT
0474	E193	68				PLA		;SCAN LIST OF CMDS FOR ENTERED CHR
0475	E194	A2	20			LDX	#MCNT	;COUNT OF COMMANDS
0476	E196	DD C4 E1			MCM2	CMP	COMB,X	;CHECK NEXT COMMAND IN LIST
0477	E199	F0	11			BEQ MCM3		;MATCH , SO PROCESS THIS COMMAND
0478	E19B CA					DEX
0479	E19C 10 F8					BPL	MCM2
0480	E19E				;IS BAD COMMAND
0481	E19E 20 D4 E7					JSR	QM
0482	E1A1 D8				COMIN	CLD
0483	E1A2 20 FE E8					JSR	LL
0484	E1A5 AE 24 A4					LDX	SAVS
0485	E1A8 9A					TXS
0486	E1A9 4C 82 E1					JMP	START

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.

Apple II manual RS6 JSR Crlow Clear Display

Models: II

RS6

JSR

CRLOW

;CLEAR DISPLAY

TXA

TAX

CMP

II specifications