Ldy Pch | Apple II specification

F884: A4 3B	181		LDY	PCH
F886: 20 96 FD	182		JSR	PRYX2
F889: 20 48 F9	183		JSR	PRBLNK	;FOLLOWED BY A BLANK
F88C: A1 3A	184		LDA	(PCL,X)	;GET OP CODE
F88E: A8	185	INSDS2	TAY
F88F: 4A	186		LSR		;EVEN/ODD TEST
F890: 90 09	187		BCC	IEVEN
F892: 6A	188		ROR		;BIT 1 TEST
F893: B0 10	189		BCS	ERR	;XXXXXX11 INVALID OP
F895: C9 A2	190		CMP	#$A2
F897: F0 0C	191		BEQ	ERR	;OPCODE $89 INVALID
F899: 29 87	192		AND	#$87	;MASK BITS
F89B: 4A	193	IEVEN	LSR		;LSB INTO CARRY FOR L/R TEST
F89C: AA	194		TAX
F89D: BD 62 F9	195		LDA	FMT1,X	;GET FORMAT INDEX BYTE
F8A0: 20 79 F8	196		JSR	SCRN2	;R/L H-BYTE ON CARRY
F8A3: D0 04	197		BNE	GETFMT
F8A5: A0 80	198	ERR	LDY	#$80	;SUBSTITUTE $80 FOR INVALID OPS
F8A7: A9 00	199		LDA	#$00	;SET PRINT FORMAT INDEX TO 0
F8A9: AA	200	GETFMT	TAX
F8AA: BD A6 F9	201		LDA	FMT2,X	;INDEX INTO PRINT FORMAT TABLE
F8AD: 85 2E	202		STA	FORMAT	;SAVE FOR ADR FIELD FORMATTING
F8AF: 29 03	203		AND	#$03	;MASK FOR 2-BIT LENGTH
	204				; (P=1 BYTE, 1=2 BYTE, 2=3 BYTE)
F8B1: 85 2F	205		STA	LENGTH
F8B3: 98	206		TYA		;OPCODE
F8B4: 29 8F	207		AND	#$8F	;MASK FOR 1XXX1010 TEST
F8B6: AA	208		TAX		; SAVE IT
F8B7: 98	209		TYA		;OPCODE TO A AGAIN
F8B8: A0 03	210		LDY	#$03
F8BA: E0 8A	211		CPX	#$8A
F8BC: F0 0B	212		BEQ	MNNDX3
F8BE: 4A	213	MNNDX1	LSR
F8BF: 90 08	214		BCC	MNNDX3	;FORM INDEX INTO MNEMONIC TABLE
F8C1: 4A	215		LSR
F8C2: 4A	216	MNNDX2	LSR		;1) 1XXX1010->00101XXX
F8C3: 09 20	217		ORA	#$20	;2) XXXYYY01->00111XXX
F8C5: 88	218		DEY		;3) XXXYYY10->00110XXX
F8C6: D0 FA	219		BNE	MNNDX2	;4) XXXYY100->00100XXX
F8C8: C8	220		INY		;5) XXXXX000->000XXXXX
F8C9: 88	221	MNNDX3	DEY
F8CA: D0 F2	222		BNE	MNNDX1
F8CC: 60	223		RTS
F8CD: FF FF FF	224		DFB $FF,$FF,$FF
F8D0: 20 82 F8	225	INSTDSP	JSR	INSDS1	;GEN FMT, LEN BYTES
F8D3: 48	226		PHA		;SAVE MNEMONIC TABLE INDEX
F8D4: B1 3A	227	PRNTOP	LDA	(PCL),Y
F8D6: 20 DA FD	228		JSR	PRBYTE
F8D9: A2 01	229		LDX	#$01	;PRINT 2 BLANKS
F8DB: 20 4A F9	230	PRNTBL	JSR	PRBL2
F8DE: C4 2F	231		CPY	LENGTH	;PRINT INST (1-3 BYTES)
F8E0: C8	232		INY		;IN A 12 CHR FIELD
F8E1: 90 F1	233		BCC	PRNTOP
F8E3: A2 03	234		LDX	#$03	;CHAR COUNT FOR MNEMONIC PRINT
F8E5: C0 04	235		CPY	#$04
F8E7: 90 F2	236		BCC	PRNTBL
F8E9: 68	237		PLA		;RECOVER MNEMONIC INDEX
F8EA: A8	238		TAY
F8EB: B9 C0 F9	239		LDA	MNEML,Y
F8EE: 85 2C	240		STA	LMNEM	;FETCH 3-CHAR MNEMONIC
F8F0: B9 00 FA	241		LDA	MNEMR,Y	; (PACKED IN 2-BYTES)
F8F3: 85 2D	242		STA	RMNEM

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 Ldy Pch

Models: II

LDY

PCH

II specifications