STA Mode | Apple II instruction

1791	8C8E 85		FD			STA	MODE
1792	8C90	20	26	8E		JSR	RDBYTX	;READ ID BYTE ON TAPE
1793	8C93	8D	00	A4		STA	DIG	;DISPLAY ON LED (NOT DECODED)
1794	8C96	CD	4E	A6		CMP	ID	;COMPARE WITH REQUESTED ID
1795	8C99	F0	29			BEQ	LOADT5	;LOAD IF EQUAL
1796	8C9B AD		4E	A6		LDA	ID	;COMPARE WITH 0
1797	8C9E C9		00			CMP	#0
1798	8CA0 F0		22			BEQ	LOADT5	;IF 0, LOAD ANYWAY
1799	8CA2 C9		FF			CMP	#$FF	;COMPARE WITH FF
1800	8CA4 F0		07			BEQ LOADT6		;IF FF, USE REQUEST SA TO LOAD
1801	8CA6
1802	8CA6 24		FD			BIT MODE		;UNWANTED RECORD, KIM OR HS?
1803	8CA8 30		16			BMI	HWRONG
1804	8CAA 4C		7B	8C		JMP LOADT2		;IF KIM, RESTART SEARCH
1805	8CAD
1806	8CAD				; SA (&EA IF USED) COME FROM REQUEST. DISCARD TAPE VALUES
1807	8CAD				; (BUFAD		ALREADY SET TO SA BY 'START')
1808	8CAD				;
1809	8CAD 20		74	8E	LOADT6 JSR RDCHK			;GET SAL FROM TAPE
1810	8CB0 20		74	8E		JSR RDCHK		;GET SAH FROM TAPE
1811	8CB3 24		FD			BIT MODE		;HS OR KIM?
1812	8CB5 10		52			BPL LOADT7		;IF KIM, START READING DATA
1813	8CB7 20		74	8E		JSR RDCHK		;HS, GET EAH, EAL FROM TAPE
1814	8CBA 20		74	8E		JSR RDCHK		; ... BUT IGNORE
1815	8CBD 4C		DE 8C			JMP LT7H		;START READING HS DATA
1816	8CC0
1817	8CC0				; SA ( & EA IF USED) COME FROM TAPE. SA REPLACES BUFAD
1818	8CC0
1819	8CC0 A9		C0		HWRONG LDA #$C0			;READ THRU TO GE TO NEXT REC
1820	8CC2 85		FD			STA MODE		;BUT DON'T CHECK CKSUM, NO FRAME ERR
1821	8CC4
1822	8CC4 20		74	8E	LOADT5 JSR RDCHK			;GET SAL FROM TAPE
1823	8CC7 85		FE			STA BUFADL		;PUT IN BUF START L
1824	8CC9 20		74	8E		JSR RDCHK		;SAME FOR SAH
1825	8CCC 85		FF			STA	BUFADH
1826	8CCE				;(SAL - H STILL HAVE REQUEST VALUE)
1827	8CCE 24		FD			BIT MODE		;HS OR KIM?
1828	8CD0 10		37			BPL LOADT7		;IF KIM, START READING RECORD
1829	8CD2 20		74	8E		JSR RDCHK		;HS. GET & SAVE EAL,EAH
1830	8CD5 8D		4A	A6		STA	EAL
1831	8CD8 20		74	8E		JSR	RDCHK
1832	8CDB 8D		4B	A6		STA	EAH
1833	8CDE
1834	8CDE				; READ HS DATA
1835	8CDE
1836	8CDE 20		E5	8D	LT7H	JSR RDBYTH		;GET NEXT BYTE
1837	8CE1 A6		FE			LDX BUFADL		;CHECK FOR END OF DATA + 1
1838	8CE3 EC		4A	A6		CPX	EAL
1839	8CE6 D0		07			BNE	LT7HA
1840	8CE8 A6		FF			LDX	BUFADH
1841	8CEA EC		4B	A6		CPX	EAH
1842	8CED F0		14			BEQ	LT7HB
1843	8CEF 20		77	8E	LT7HA	JSR	CHKT	;NOT END, UPDATE CHECKSUM
1844	8CF2 24		FD			BIT	MODE	;WRONG RECORD?
1845	8CF4 70		04			BVS	LT7HC	;IF SO, DONT STORE BYTE
1846	8CF6 A0		00			LDY	#0	;STORE BYTE
1847	8CF8 91		FE			STA	(BUFADL),Y
1848	8CFA E6		FE		LT7HC	INC	BUFADL	;BUMP BUFFER ADDR
1849	8CFC D0		E0			BNE	LT7H
1850	8CFE E6		FF			INC	BUFADH	;CARRY
1851	8D00	4C	DE 8C			JMP	LT7H
1852	8D03

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.

STA

MODE

CMP

CMP

CMP

II specifications