STA STIY+2 | Apple II guide

1779	EB85 8D 29 A4		STA	STIY+2
1780	EB88 8D 2C A4		STA	CPIY+2
1781	EB8B A9 99		LDA	#$99	;STA INSTR
1782	EB8D 8D 27 A4		STA	STIY
1783	EB90 A9 D9		LDA	#$D9	;CMP INSTR
1784	EB92 8D 2A A4		STA	CPIY
1785	EB95 A9 60		LDA	#$60	;RTS
1786	EB97 8D 2D A4		STA	LDIY+3
1787	EB9A 68		PLA
1788	EB9B 4C 27 A4		JMP STIY		;START EXECUTING STA (),Y
1789	EB9E
1790	EB9E	;PUSH X & Y WITHOUT CHANGING THE REGS
1791	EB9E 8D 2D A4	PHXY	STA CPIY+3		;SAVE ACC
1792	EBA1 98		TYA
1793	EBA2 48		PHA		;PUSH Y
1794	EBA3 8A		TXA
1795	EBA4 48		PHA		;PUSH X
1796	EBA5 20 BA EB		JSR	SWSTAK	;SWAP X , Y WITH RTRN ADDR FROM S`
1797	EBA8 AD 2D A4		LDA	CPIY+3
1798	EBAB 60		RTS
1799	EBAC
1800	EBAC	;PULL X & Y WITHOUT CHANGING ACC
1801	EBAC	;IT HAS TO		BE CALLED BY JSR & NOT BY JMP INSTR
1802	EBAC	;SINCE IT SWAPS THE STACK
1803	EBAC 8D 2D A4	PLXY	STA	CPIY+3
1804	EBAF 20 BA EB		JSR SWSTAK		;SWAP X , Y WITH RTRN ADDR FROM`
1805	EBB2 68		PLA
1806	EBB3 AA		TAX		;PULL X
1807	EBB4 68		PLA
1808	EBB5 A8		TAY		;PULL Y
1809	EBB6 AD 2D A4		LDA	CPIY+3
1810	EBB9 60		RTS
1811	EBBA
1812	EBBA	;SWAP STACK
1813	EBBA BA	SWSTAK TSX
1814	EBBB A9 02		LDA	#2
1815	EBBD 48	SWST1	PHA
1816	EBBE BD 06 01		LDA	$0106,X	;GET PCH OR PCL
1817	EBC1 BC 04 01		LDY	$0104,X	;GET Y OR X REGS
1818	EBC4 9D 04 01		STA	$0104,X
1819	EBC7 98		TYA
1820	EBC8 9D 06 01		STA	$0106,X
1821	EBCB CA		DEX
1822	EBCC 68		PLA
1823	EBCD 38		SEC
1824	EBCE E9 01		SBC	#1
1825	EBD0 D0 EB		BNE	SWST1
1826	EBD2 BD 08 01		LDA	$0108,X	;RESTORE Y & X FROM STACK
1827	EBD5 A8		TAY
1828	EBD6 BD 07 01		LDA	$0107,X
1829	EBD9 AA		TAX
1830	EBDA 60		RTS
1831	EBDB
1832	EBDB	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
1833	EBDB	;GET A CHAR FROM TTY SUBR INTO ACC ,SAVES X
1834	EBDB 8A	GETTTY TXA			;SAVE X
1835	EBDC 48		PHA
1836	EBDD A2 07		LDX #$07		;SET UP FOR 8 BIT CNT
1837	EBDF 8E 2A A4		STX CPIY		;CLR MSB
1838	EBE2 2C 00 A8	GET1	BIT DRB		;A^M , PB6->V
1839	EBE5 70 FB		BVS GET1		;WAIT FOR START BIT
1840	EBE7 20 0F EC		JSR DELAY		;DELAY 1 BIT

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 STA STIY+2

Models: II

STA

STIY+2

II specifications