mirror of
https://github.com/cc65/cc65.git
synced 2024-06-01 13:41:34 +00:00
dacee3b9ed
All but one TGI drivers didn't use IRQs. Especially when the TGI driver kernel was the only .interruptor this meant quite some unnecessary overhead because it pulled in the whole IRQ infrastructure. The one driver using IRQs (the graphics driver for the 160x102x16 mode on the Lynx) now uses a library reference to set up a JMP to its IRQ handler.
794 lines
21 KiB
ArmAsm
794 lines
21 KiB
ArmAsm
;
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; Graphics driver for the 640x480x2 mode on the C128 VDC 64k
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; (values for this mode based on Fred Bowen's document)
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; Maciej 'YTM/Elysium' Witkowiak <ytm@elysium.pl>
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; 23.12.2002
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; 2004-04-04, Greg King
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;
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; NOTES:
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; For any smart monkey that will try to optimize this: PLEASE do tests on
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; real VDC, not only VICE.
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;
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; Only DONE routine contains C128-mode specific stuff, everything else will
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; work in C64-mode of C128 (C64 needs full VDC init then).
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;
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; With special initialization and CALC we can get 320x200 double-pixel mode.
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;
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; Color translation values for BROWN and GRAY3 are obviously wrong, they
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; could be replaced by equiv. of ORANGE and GRAY2 but this would give only
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; 14 of 16 colors available.
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;
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; Register 25 ($19) is said to require different value for VDC v1, but I
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; couldn't find what it should be.
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.include "zeropage.inc"
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.include "tgi-kernel.inc"
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.include "tgi-error.inc"
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.macpack generic
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.macpack module
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; ------------------------------------------------------------------------
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; Constants
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VDC_ADDR_REG = $D600 ; VDC address
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VDC_DATA_REG = $D601 ; VDC data
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VDC_DSP_HI = 12 ; registers used
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VDC_DSP_LO = 13
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VDC_DATA_HI = 18
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VDC_DATA_LO = 19
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VDC_VSCROLL = 24
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VDC_HSCROLL = 25
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VDC_COLORS = 26
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VDC_CSET = 28
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VDC_COUNT = 30
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VDC_DATA = 31
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; ------------------------------------------------------------------------
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; Header. Includes jump table and constants.
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module_header _c128_vdc2_tgi
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; First part of the header is a structure that has a magic and defines the
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; capabilities of the driver
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.byte $74, $67, $69 ; "tgi"
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.byte TGI_API_VERSION ; TGI API version number
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.addr $0000 ; Library reference
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xres: .word 640 ; X resolution
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yres: .word 480 ; Y resolution
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.byte 2 ; Number of drawing colors
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pages: .byte 0 ; Number of screens available
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.byte 8 ; System font X size
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.byte 8 ; System font Y size
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.word $0100 ; Aspect ratio (based on 4/3 display)
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.byte 0 ; TGI driver flags
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; Next comes the jump table. Currently all entries must be valid and may point
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; to an RTS for test versions (function not implemented).
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.addr INSTALL
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.addr UNINSTALL
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.addr INIT
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.addr DONE
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.addr GETERROR
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.addr CONTROL
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.addr CLEAR
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.addr SETVIEWPAGE
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.addr SETDRAWPAGE
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.addr SETCOLOR
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.addr SETPALETTE
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.addr GETPALETTE
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.addr GETDEFPALETTE
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.addr SETPIXEL
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.addr GETPIXEL
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.addr LINE
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.addr BAR
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.addr TEXTSTYLE
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.addr OUTTEXT
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; ------------------------------------------------------------------------
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; Data.
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; Variables mapped to the zero page segment variables. Some of these are
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; used for passing parameters to the driver.
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X1 = ptr1
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Y1 = ptr2
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X2 = ptr3
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Y2 = ptr4
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ADDR = tmp1
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TEMP = tmp3
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TEMP2 = tmp4 ; HORLINE
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TEMP3 = sreg ; HORLINE
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; Absolute variables used in the code
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.bss
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ERROR: .res 1 ; Error code
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PALETTE: .res 2 ; The current palette
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BITMASK: .res 1 ; $00 = clear, $FF = set pixels
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OLDCOLOR: .res 1 ; colors before entering gfx mode
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; Text output stuff
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TEXTMAGX: .res 1
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TEXTMAGY: .res 1
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TEXTDIR: .res 1
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; Constants and tables
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.rodata
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DEFPALETTE: .byte $00, $0f ; White on black
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PALETTESIZE = * - DEFPALETTE
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BITTAB: .byte $80,$40,$20,$10,$08,$04,$02,$01
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BITMASKL: .byte %11111111, %01111111, %00111111, %00011111
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.byte %00001111, %00000111, %00000011, %00000001
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BITMASKR: .byte %10000000, %11000000, %11100000, %11110000
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.byte %11111000, %11111100, %11111110, %11111111
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; color translation table (indexed by VIC color)
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COLTRANS: .byte $00, $0f, $08, $06, $0a, $04, $02, $0c
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.byte $0d, $0b, $09, $01, $0e, $05, $03, $07
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; colors BROWN and GRAY3 are wrong
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; VDC initialization table (reg),(val),...,$ff
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InitVDCTab:
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.byte VDC_DSP_HI, 0 ; viewpage 0 as default
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.byte VDC_DSP_LO, 0
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.byte VDC_HSCROLL, $87
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.byte 2, $66
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.byte 4, $4c
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.byte 5, $06
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.byte 6, $4c
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.byte 7, $47
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.byte 8, $03
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.byte 9, $06
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.byte 27, $00
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.byte $ff
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SCN80CLR: .byte 27,88,147,27,88,0
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.code
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; ------------------------------------------------------------------------
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; INSTALL routine. Is called after the driver is loaded into memory. May
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; initialize anything that has to be done just once. Is probably empty
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; most of the time.
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;
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; Must set an error code: NO
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;
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INSTALL:
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; check for VDC version and update register $19 value
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; check for VDC ram size and update number of available screens
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ldx #VDC_CSET ; determine size of RAM...
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jsr VDCReadReg
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sta tmp1
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ora #%00010000
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jsr VDCWriteReg ; turn on 64k
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jsr settestadr1 ; save original value of test byte
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jsr VDCReadByte
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sta tmp2
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lda #$55 ; write $55 here
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ldy #ptr1
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jsr test64k ; read it here and there
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lda #$aa ; write $aa here
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ldy #ptr2
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jsr test64k ; read it here and there
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jsr settestadr1
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lda tmp2
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jsr VDCWriteByte ; restore original value of test byte
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lda ptr1 ; do bytes match?
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cmp ptr1+1
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bne @have64k
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lda ptr2
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cmp ptr2+1
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bne @have64k
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ldx #VDC_CSET
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lda tmp1
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jsr VDCWriteReg ; restore 16/64k flag
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jmp @endok ; and leave default values for 16k
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@have64k:
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lda #1
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sta pages
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@endok:
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rts
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test64k:
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sta tmp1
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sty ptr3
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lda #0
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sta ptr3+1
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jsr settestadr1
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lda tmp1
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jsr VDCWriteByte ; write $55
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jsr settestadr1
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jsr VDCReadByte ; read here
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pha
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jsr settestadr2
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jsr VDCReadByte ; and there
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ldy #1
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sta (ptr3),y
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pla
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dey
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sta (ptr3),y
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rts
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settestadr1:
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ldy #$02 ; test page 2 (here)
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.byte $2c
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settestadr2:
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ldy #$42 ; or page 64+2 (there)
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lda #0
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jmp VDCSetSourceAddr
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; ------------------------------------------------------------------------
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; UNINSTALL routine. Is called before the driver is removed from memory. May
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; clean up anything done by INSTALL but is probably empty most of the time.
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;
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; Must set an error code: NO
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;
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UNINSTALL:
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rts
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; ------------------------------------------------------------------------
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; INIT: Changes an already installed device from text mode to graphics
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; mode.
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; Note that INIT/DONE may be called multiple times while the driver
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; is loaded, while INSTALL is only called once, so any code that is needed
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; to initializes variables and so on must go here. Setting palette and
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; clearing the screen is not needed because this is called by the graphics
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; kernel later.
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; The graphics kernel will never call INIT when a graphics mode is already
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; active, so there is no need to protect against that.
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;
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; Must set an error code: YES
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;
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INIT:
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lda pages ; is there enough memory?
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bne @L1 ; Jump if there is one screen
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lda #TGI_ERR_INV_MODE ; Error
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bne @L9
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; Initialize variables
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@L1: ldx #$FF
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stx BITMASK
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; Remeber current color value
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ldx #VDC_COLORS
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jsr VDCReadReg
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sta OLDCOLOR
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; Switch into graphics mode (set view page 0)
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ldy #0
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@L2: ldx InitVDCTab,y
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bmi @L3
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iny
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lda InitVDCTab,y
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jsr VDCWriteReg
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iny
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bne @L2
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@L3:
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; Done, reset the error code
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lda #TGI_ERR_OK
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@L9: sta ERROR
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rts
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; ------------------------------------------------------------------------
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; DONE: Will be called to switch the graphics device back into text mode.
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; The graphics kernel will never call DONE when no graphics mode is active,
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; so there is no need to protect against that.
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;
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; Must set an error code: NO
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;
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DONE:
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; This part is C128-mode specific
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jsr $e179 ; reload character set and setup VDC
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jsr $ff62
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lda $d7 ; in 80-columns?
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bne @L01
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@L0: lda SCN80CLR,y
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beq @L1
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jsr $ffd2 ; print \xe,clr,\xe
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iny
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bne @L0
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@L01: lda #147
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jsr $ffd2 ; print clr
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@L1: lda #0 ; restore view page
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ldx #VDC_DSP_HI
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jsr VDCWriteReg
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lda OLDCOLOR
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ldx #VDC_COLORS
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jsr VDCWriteReg ; restore color (background)
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lda #$47
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ldx #VDC_HSCROLL
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jmp VDCWriteReg ; switch to text screen
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; ------------------------------------------------------------------------
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; GETERROR: Return the error code in A and clear it.
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GETERROR:
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ldx #TGI_ERR_OK
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lda ERROR
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stx ERROR
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rts
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; ------------------------------------------------------------------------
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; CONTROL: Platform/driver specific entry point.
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;
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; Must set an error code: YES
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;
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CONTROL:
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lda #TGI_ERR_INV_FUNC
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sta ERROR
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rts
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; ------------------------------------------------------------------------
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; CLEAR: Clears the screen.
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;
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; Must set an error code: NO
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;
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CLEAR:
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lda #0
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tay
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jsr VDCSetSourceAddr
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lda #0
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ldx #VDC_VSCROLL
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jsr VDCWriteReg ; set fill mode
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lda #0
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jsr VDCWriteByte ; put 1rst byte (fill value)
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ldy #159 ; 159 times
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lda #0 ; 256 bytes
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ldx #VDC_COUNT
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@L1: jsr VDCWriteReg
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dey
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bne @L1
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rts
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; ------------------------------------------------------------------------
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; SETVIEWPAGE: Set the visible page. Called with the new page in A (0..n).
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; The page number is already checked to be valid by the graphics kernel.
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;
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; Must set an error code: NO (will only be called if page ok)
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;
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SETVIEWPAGE:
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rts
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; ------------------------------------------------------------------------
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; SETDRAWPAGE: Set the drawable page. Called with the new page in A (0..n).
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; The page number is already checked to be valid by the graphics kernel.
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;
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; Must set an error code: NO (will only be called if page ok)
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;
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SETDRAWPAGE:
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rts
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; ------------------------------------------------------------------------
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; SETCOLOR: Set the drawing color (in A). The new color is already checked
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; to be in a valid range (0..maxcolor-1).
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;
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; Must set an error code: NO (will only be called if color ok)
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;
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SETCOLOR:
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tax
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beq @L1
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lda #$FF
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@L1: sta BITMASK
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rts
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; ------------------------------------------------------------------------
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; SETPALETTE: Set the palette (not available with all drivers/hardware).
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; A pointer to the palette is passed in ptr1. Must set an error if palettes
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; are not supported
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;
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; Must set an error code: YES
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;
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SETPALETTE:
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ldy #PALETTESIZE - 1
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@L1: lda (ptr1),y ; Copy the palette
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and #$0F ; Make a valid color
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sta PALETTE,y
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dey
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bpl @L1
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; Get the color entries from the palette
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ldy PALETTE+1 ; Foreground color
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lda COLTRANS,y
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asl a
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asl a
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asl a
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asl a
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ldy PALETTE ; Background color
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ora COLTRANS,y
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ldx #VDC_COLORS
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jsr VDCWriteReg
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lda #TGI_ERR_OK ; Clear error code
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sta ERROR
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rts
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; ------------------------------------------------------------------------
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; GETPALETTE: Return the current palette in A/X. Even drivers that cannot
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; set the palette should return the default palette here, so there's no
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; way for this function to fail.
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;
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; Must set an error code: NO
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;
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GETPALETTE:
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lda #<PALETTE
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ldx #>PALETTE
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rts
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; ------------------------------------------------------------------------
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; GETDEFPALETTE: Return the default palette for the driver in A/X. All
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; drivers should return something reasonable here, even drivers that don't
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; support palettes, otherwise the caller has no way to determine the colors
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; of the (not changeable) palette.
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;
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; Must set an error code: NO (all drivers must have a default palette)
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;
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GETDEFPALETTE:
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lda #<DEFPALETTE
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ldx #>DEFPALETTE
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rts
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; ------------------------------------------------------------------------
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; SETPIXEL: Draw one pixel at X1/Y1 = ptr1/ptr2 with the current drawing
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; color. The coordinates passed to this function are never outside the
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; visible screen area, so there is no need for clipping inside this function.
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;
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; Must set an error code: NO
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;
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SETPIXEL:
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jsr CALC ; Calculate coordinates
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stx TEMP
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lda ADDR
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ldy ADDR+1
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jsr VDCSetSourceAddr
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jsr VDCReadByte
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ldx TEMP
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sta TEMP
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eor BITMASK
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and BITTAB,X
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eor TEMP
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pha
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lda ADDR
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ldy ADDR+1
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jsr VDCSetSourceAddr
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pla
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jsr VDCWriteByte
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@L9: rts
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; ------------------------------------------------------------------------
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; GETPIXEL: Read the color value of a pixel and return it in A/X. The
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; coordinates passed to this function are never outside the visible screen
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; area, so there is no need for clipping inside this function.
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GETPIXEL:
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jsr CALC ; Calculate coordinates
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stx TEMP ; preserve X
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lda ADDR
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ldy ADDR+1
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jsr VDCSetSourceAddr
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jsr VDCReadByte
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ldx TEMP
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ldy #$00
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and BITTAB,X
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beq @L1
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iny
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@L1: tya ; Get color value into A
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ldx #$00 ; Clear high byte
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rts
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; ------------------------------------------------------------------------
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; BAR: Draw a filled rectangle with the corners X1/Y1, X2/Y2, where
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; X1/Y1 = ptr1/ptr2 and X2/Y2 = ptr3/ptr4 using the current drawing color.
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; Contrary to most other functions, the graphics kernel will sort and clip
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; the coordinates before calling the driver, so on entry the following
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; conditions are valid:
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; X1 <= X2
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; Y1 <= Y2
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; (X1 >= 0) && (X1 < XRES)
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; (X2 >= 0) && (X2 < XRES)
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; (Y1 >= 0) && (Y1 < YRES)
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; (Y2 >= 0) && (Y2 < YRES)
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;
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; Must set an error code: NO
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;
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BAR:
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inc Y2
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bne HORLINE
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inc Y2+1
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; Original code for a horizontal line
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HORLINE:
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lda X1
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pha
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lda X1+1
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pha
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jsr CALC ; get data for LEFT
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lda BITMASKL,x ; remember left address and bitmask
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pha
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lda ADDR
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pha
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lda ADDR+1
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pha
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lda X2
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sta X1
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lda X2+1
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sta X1+1
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jsr CALC ; get data for RIGHT
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lda BITMASKR,x
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sta TEMP3
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pla ; recall data for LEFT
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sta X1+1
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pla
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sta X1 ; put left address into X1
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pla
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cmp #%11111111 ; if left bit <> 0
|
|
beq @L1
|
|
sta TEMP2 ; do left byte only...
|
|
lda X1
|
|
ldy X1+1
|
|
jsr VDCSetSourceAddr
|
|
jsr VDCReadByte
|
|
sta TEMP
|
|
eor BITMASK
|
|
and TEMP2
|
|
eor TEMP
|
|
pha
|
|
lda X1
|
|
ldy X1+1
|
|
jsr VDCSetSourceAddr
|
|
pla
|
|
jsr VDCWriteByte
|
|
inc X1 ; ... and proceed
|
|
bne @L1
|
|
inc X1+1
|
|
|
|
; do right byte (if Y2=0 ++ADDR and skip)
|
|
@L1: lda TEMP3
|
|
cmp #%11111111 ; if right bit <> 7
|
|
bne @L11
|
|
inc ADDR ; right bit = 7 - the next one is the last
|
|
bne @L10
|
|
inc ADDR+1
|
|
@L10: bne @L2
|
|
|
|
@L11: lda ADDR ; do right byte only...
|
|
ldy ADDR+1
|
|
jsr VDCSetSourceAddr
|
|
jsr VDCReadByte
|
|
sta TEMP
|
|
eor BITMASK
|
|
and TEMP3
|
|
eor TEMP
|
|
pha
|
|
lda ADDR
|
|
ldy ADDR+1
|
|
jsr VDCSetSourceAddr
|
|
pla
|
|
jsr VDCWriteByte
|
|
|
|
@L2: ; do the fill in the middle
|
|
lda ADDR ; calculate offset in full bytes
|
|
sec
|
|
sbc X1
|
|
beq @L3 ; if equal - there are no more bytes
|
|
sta ADDR
|
|
|
|
lda X1 ; setup for the left side
|
|
ldy X1+1
|
|
jsr VDCSetSourceAddr
|
|
lda BITMASK ; get color
|
|
jsr VDCWriteByte ; put 1st value
|
|
ldx ADDR
|
|
dex
|
|
beq @L3 ; 1 byte already written
|
|
|
|
stx ADDR ; if there are more bytes - fill them...
|
|
ldx #VDC_VSCROLL
|
|
lda #0
|
|
jsr VDCWriteReg ; setup for fill
|
|
ldx #VDC_COUNT
|
|
lda ADDR
|
|
jsr VDCWriteReg ; ... fill them NOW!
|
|
|
|
@L3: pla
|
|
sta X1+1
|
|
pla
|
|
sta X1
|
|
|
|
; End of horizontal line code
|
|
|
|
inc Y1
|
|
bne @L4
|
|
inc Y1+1
|
|
@L4: lda Y1
|
|
cmp Y2
|
|
bne @L5
|
|
lda Y1+1
|
|
cmp Y2+1
|
|
bne @L5
|
|
rts
|
|
|
|
@L5: jmp HORLINE
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
|
; TEXTSTYLE: Set the style used when calling OUTTEXT. Text scaling in X and Y
|
|
; direction is passend in X/Y, the text direction is passed in A.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
TEXTSTYLE:
|
|
stx TEXTMAGX
|
|
sty TEXTMAGY
|
|
sta TEXTDIR
|
|
rts
|
|
|
|
|
|
; ------------------------------------------------------------------------
|
|
; OUTTEXT: Output text at X/Y = ptr1/ptr2 using the current color and the
|
|
; current text style. The text to output is given as a zero terminated
|
|
; string with address in ptr3.
|
|
;
|
|
; Must set an error code: NO
|
|
;
|
|
|
|
OUTTEXT:
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
; Calculate all variables to plot the pixel at X1/Y1.
|
|
;------------------------
|
|
;< X1,Y1 - pixel
|
|
;> ADDR - address of card
|
|
;> X - bit number (X1 & 7)
|
|
CALC:
|
|
lda Y1
|
|
pha
|
|
lda Y1+1
|
|
pha
|
|
lsr
|
|
ror Y1 ; Y=Y/2
|
|
sta Y1+1
|
|
sta ADDR+1
|
|
lda Y1
|
|
asl
|
|
rol ADDR+1
|
|
asl
|
|
rol ADDR+1 ; Y*4
|
|
clc
|
|
adc Y1
|
|
sta ADDR
|
|
lda Y1+1
|
|
adc ADDR+1
|
|
sta ADDR+1 ; Y*4+Y=Y*5
|
|
lda ADDR
|
|
asl
|
|
rol ADDR+1
|
|
asl
|
|
rol ADDR+1
|
|
asl
|
|
rol ADDR+1
|
|
asl
|
|
rol ADDR+1
|
|
sta ADDR ; Y*5*16=Y*80
|
|
lda X1+1
|
|
sta TEMP
|
|
lda X1
|
|
lsr TEMP
|
|
ror
|
|
lsr TEMP
|
|
ror
|
|
lsr TEMP
|
|
ror
|
|
clc
|
|
adc ADDR
|
|
sta ADDR
|
|
lda ADDR+1 ; ADDR = Y*80+x/8
|
|
adc TEMP
|
|
sta ADDR+1
|
|
pla
|
|
sta Y1+1
|
|
pla
|
|
sta Y1
|
|
and #1
|
|
beq @even ; even line - no offset
|
|
lda ADDR
|
|
clc
|
|
adc #<21360
|
|
sta ADDR
|
|
lda ADDR+1
|
|
adc #>21360
|
|
sta ADDR+1 ; odd lines are 21360 bytes farther
|
|
@even: lda X1
|
|
and #7
|
|
tax
|
|
rts
|
|
|
|
;-------------
|
|
; VDC helpers
|
|
|
|
VDCSetSourceAddr:
|
|
pha
|
|
tya
|
|
ldx #VDC_DATA_HI
|
|
jsr VDCWriteReg
|
|
pla
|
|
ldx #VDC_DATA_LO
|
|
bne VDCWriteReg
|
|
|
|
VDCReadByte:
|
|
ldx #VDC_DATA
|
|
VDCReadReg:
|
|
stx VDC_ADDR_REG
|
|
@L0: bit VDC_ADDR_REG
|
|
bpl @L0
|
|
lda VDC_DATA_REG
|
|
rts
|
|
|
|
VDCWriteByte:
|
|
ldx #VDC_DATA
|
|
VDCWriteReg:
|
|
stx VDC_ADDR_REG
|
|
@L0: bit VDC_ADDR_REG
|
|
bpl @L0
|
|
sta VDC_DATA_REG
|
|
rts
|
|
|
|
; ------------------------------------------------------------------------
|
|
|
|
.include "../../tgi/tgidrv_line.inc"
|