💾 Archived View for spam.works › mirrors › textfiles › apple › appswitc.app captured on 2023-06-14 at 15:44:08.

View Raw

More Information

-=-=-=-=-=-=-

/----------------------------------------------------------------------------\
	   Apple //e Soft Switch, Status, and other I/O locations
\----------------------------------------------------------------------------/

MEMORY MANAGEMENT SOFT SWITCHES

$C000	W	80STOREOFF	Allow page2 to switch video page1 page2
$C001	W	80STOREON	Allow page2 to switch main & aux video memory
$C002	W	RAMRDOFF	Read enable main memory from $0200-$BFFF
$C003	W	RAMDRON 	Read enable aux memory from $0200-$BFFF
$C004	W	RAMWRTOFF	Write enable main memory from $0200-$BFFF
$C005	W	RAMWRTON	Write enable aux memory from $0200-$BFFF
$C006	W	INTCXROMOFF	Enable slot ROM from $C100-$CFFF
$C007	W	INTCXROMON	Enable main ROM from $C100-$CFFF
$C008	W	ALZTPOFF	Enable main memory from $0000-$01FF & avl BSR
$C009	W	ALTZPON 	Enable aux memory from $0000-$01FF & avl BSR
$C00A	W	SLOTC3ROMOFF	Enable main ROM from $C300-$C3FF
$C00B	W	SLOTC3ROMON	Enable slot ROM from $C300-$C3FF

VIDEO SOFT SWITCHES

$C00C	W	80COLOFF	Turn off 80 column display
$C00D	W	80COLON 	Turn on 80 column display
$C00E	W	ALTCHARSETOFF	Turn off alternate characters
$C00F	W	ALTCHARSETON	Turn on alternate characters
$C050	R/W	TEXTOFF 	Select graphics mode
$C051	R/W	TEXTON		Select text mode
$C052	R/W	MIXEDOFF	Use full screen for graphics
$C053	R/W	MIXEDON 	Use graphics with 4 lines of text
$C054	R/W	PAGE2OFF	Select panel display (or main video memory)
$C055	R/W	PAGE2ON 	Select page2 display (or aux video memory)
$C056	R/W	HIRESOFF	Select low resolution graphics
$C057	R/W	HIRESON 	Select high resolution graphics

SOFT SWITCH STATUS FLAGS

$C010	R7	AKD		1=key pressed	0=keys free    (clears strobe)
$C011	R7	BSRBANK2	1=bank2 available    0=bank1 available
$C012	R7	BSRREADRAM	1=BSR active for read	0=$D000-$FFFF active
$C013	R7	RAMRD		0=main $0200-$BFFF active reads  1=aux active
$C014	R7	RAMWRT		0=main $0200-$BFFF active writes 1=aux writes
$C015	R7	INTCXROM	1=main $C100-$CFFF ROM active	0=slot active
$C016	R7	ALTZP		1=aux $0000-$1FF+auxBSR    0=main available
$C017	R7	SLOTC3ROM	1=slot $C3 ROM active	0=main $C3 ROM active
$C018	R7	80STORE 	1=page2 switches main/aux   0=page2 video
$C019	R7	VERTBLANK	1=vertical retrace on	0=vertical retrace off
$C01A	R7	TEXT		1=text mode is active	0=graphics mode active
$C01B	R7	MIXED		1=mixed graphics & text    0=full screen
$C01C	R7	PAGE2		1=video page2 selected or aux
$C01D	R7	HIRES		1=high resolution graphics   0=low resolution
$C01E	R7	ALTCHARSET	1=alt character set on	  0=alt char set off
$C01F	R7	80COL		1=80 col display on	0=80 col display off
\============================================================================/