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JimmyDansbo/helloworld_vera_rom_acme.asm

Created December 26, 2020 10:11
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Hello World as a Commander X16 ROM image
Raw
helloworld_vera_rom_acme.asm
!cpu 65c02
VERA_ADDR_L = $9F20
VERA_ADDR_M = $9F21
VERA_ADDR_H = $9F22
VERA_DATA0 = $9F23
VERA_CTRL = $9F25
VERA_DC_VIDEO = $9F29
VERA_DC_HSCALE = $9F2A
VERA_DC_VSCALE = $9F2B
VERA_DC_HSTOP = $9F2A
VERA_DC_VSTOP = $9F2C
VERA_L1_CONFIG = $9F34
VERA_L1_TILEBASE = $9F36
Print_var = $30
Print_col = $32
*=$C000 ; since this is a Commander X16, the ROM starts loading at $C000
Reset:
jsr VERA_init_text_80x60
; Set the X/Y coordinates to 0 0
lda #%00010000 ; Increment 1, High-addr=0
sta VERA_ADDR_H
stz VERA_ADDR_M ; Y coordinate
stz VERA_ADDR_L ; X coordinate
; print COMMANDER X16
lda #<my_str
sta Print_var
lda #>my_str
sta Print_var+1
; White on black = $01
lda #$01
sta Print_col
jsr VERA_print_line
lda #30 ; Y coordinate (middle of screen)
sta VERA_ADDR_M
lda #64 ; X coordinate: (screenwidth/2)-(stringlength/2)
sta VERA_ADDR_L ; multiplied by 2 because in normal screemode,
; 1 byte is used for character and 1 for color
; print HELLO WORLD
lda #<my_str2
sta Print_var
lda #>my_str2
sta Print_var+1
; White on blue = $61
lda #$61
sta Print_col
jsr VERA_print_line
.end: bra .end
; Initialize the VERA in 80x60 text mode
VERA_init_text_80x60:
; load the font
jsr VERA_load_font
; reset the rest of the device
; +--------- Current field
; |+-------- Sprite Enable
; ||+------- Layer 1 enable
; |||+------ Layer 0 enable
; ||||+----- not used
; |||||+---- Chroma disable
; ||||||++-- Output mode
lda #%00100001 ; C=Chrome Disable, O=Outputmode, (1=vga)
sta VERA_DC_VIDEO
lda #128 ; Hscale - 128=normal, 64=2x
sta VERA_DC_HSCALE
lda #128 ; vscale - 128=Normal, 64=2x
sta VERA_DC_VSCALE
; ++-------- Map Height 01
; ||
; ||++------ Map Width 10
; ||||
; ||||+----- T256C 0
; |||||+---- Bitmap mode 0
; ||||||++-- Colour depth 00
lda #%01100000
sta VERA_L1_CONFIG
; ++++++---- Tile base address
; ||||||+--- Height
; |||||||+-- Width
lda #%01111100
sta VERA_L1_TILEBASE
; R------A R=Reset, A= Adress (port 1 / 2)
lda #%00000000
sta VERA_CTRL
; Set the X/Y coordinates to 0 0
lda #%00010000 ; Increment 1, High-addr=0
sta VERA_ADDR_H
lda #0 ; Y coordinate
sta VERA_ADDR_M
sta VERA_ADDR_L ; X coordinate
; Clear the screen with black background
ldx #80
ldy #60
@loop:
lda #$20 ; Space character
sta VERA_DATA0
lda #$01 ; White on black
sta VERA_DATA0
dex
bne @loop
ldx #80
inc VERA_ADDR_M
stz VERA_ADDR_L
dey
bne @loop
rts
VERA_print_line:
ldx Print_col ; Load colors to use
ldy #0 ; Use .Y as index into string
@loop:
lda (Print_var),y
beq @end ; If it is 0, jump to end
sta VERA_DATA0 ; Write character to VERA memory, VERA
; will automaticly add 2 to address.
stx VERA_DATA0 ; Write color information
iny ; Increment .Y
bra @loop ; Jump back to get next character
@end:
rts
; Loading the font from the font data still has gaps. For one it only loads the first 32 characters.
; |- Hacked to make 2 loops to get all characters from font data
VERA_load_font:
stz VERA_CTRL
stz VERA_ADDR_L
lda #$F8
sta VERA_ADDR_M
lda #$10
sta VERA_ADDR_H
lda #<VERA_FONT_DATA
sta Print_var
lda #>VERA_FONT_DATA
sta Print_var+1
ldy #0
@loop1:
lda (Print_var),y
sta VERA_DATA0
iny
bne @loop1
inc Print_var+1
ldy #0
@loop2:
lda (Print_var),y
sta VERA_DATA0
iny
bne @loop2
rts
VERA_FONT_DATA:
!byte %01111100, %11000110, %11011110, %11011110, %11011110, %11000000, %01111000, %00000000 ; @ 0
!byte %00110000, %01111000, %11001100, %11001100, %11111100, %11001100, %11001100, %00000000 ; A 1
!byte %11111100, %01100110, %01100110, %01111100, %01100110, %01100110, %11111100, %00000000 ; B 2
!byte %00111100, %01100110, %11000000, %11000000, %11000000, %01100110, %00111100, %00000000 ; C 3
!byte %11111000, %01101100, %01100110, %01100110, %01100110, %01101100, %11111000, %00000000 ; D 4
!byte %11111110, %01100010, %01101000, %01111000, %01101000, %01100010, %11111110, %00000000 ; E 5
!byte %11111110, %01100010, %01101000, %01111000, %01101000, %01100000, %11110000, %00000000 ; F 6
!byte %00111100, %01100110, %11000000, %11000000, %11001110, %01100110, %00111110, %00000000 ; G 7
!byte %11001100, %11001100, %11001100, %11111100, %11001100, %11001100, %11001100, %00000000 ; H 8
!byte %01111000, %00110000, %00110000, %00110000, %00110000, %00110000, %01111000, %00000000 ; I 9
!byte %00011110, %00001100, %00001100, %00001100, %11001100, %11001100, %01111000, %00000000 ; J 10
!byte %11100110, %01100110, %01101100, %01111000, %01101100, %01100110, %11100110, %00000000 ; K 11
!byte %11110000, %01100000, %01100000, %01100000, %01100010, %01100110, %11111110, %00000000 ; L 12
!byte %11000110, %11101110, %11111110, %11111110, %11010110, %11000110, %11000110, %00000000 ; M 13
!byte %11000110, %11100110, %11110110, %11011110, %11001110, %11000110, %11000110, %00000000 ; N 14
!byte %00111000, %01101100, %11000110, %11000110, %11000110, %01101100, %00111000, %00000000 ; O 15
!byte %11111100, %01100110, %01100110, %01111100, %01100000, %01100000, %11110000, %00000000 ; P 16
!byte %01111000, %11001100, %11001100, %11001100, %11011100, %01111000, %00011100, %00000000 ; Q 17
!byte %11111100, %01100110, %01100110, %01111100, %01101100, %01100110, %11100110, %00000000 ; R 18
!byte %01111000, %11001100, %11100000, %01110000, %00011100, %11001100, %01111000, %00000000 ; S 19
!byte %11111100, %10110100, %00110000, %00110000, %00110000, %00110000, %01111000, %00000000 ; T 20
!byte %11001100, %11001100, %11001100, %11001100, %11001100, %11001100, %11111100, %00000000 ; U 21
!byte %11001100, %11001100, %11001100, %11001100, %11001100, %01111000, %00110000, %00000000 ; V 22
!byte %11000110, %11000110, %11000110, %11010110, %11111110, %11101110, %11000110, %00000000 ; W 23
!byte %11000110, %11000110, %01101100, %00111000, %00111000, %01101100, %11000110, %00000000 ; X 24
!byte %11001100, %11001100, %11001100, %01111000, %00110000, %00110000, %01111000, %00000000 ; Y 25
!byte %11111110, %11000110, %10001100, %00011000, %00110010, %01100110, %11111110, %00000000 ; Z 26
!byte %01111000, %01100000, %01100000, %01100000, %01100000, %01100000, %01111000, %00000000 ; [ 27
!byte %00001100, %00010010, %00110000, %01111100, %00110000, %01100010, %11111100, %00000000 ; £ 28
!byte %01111000, %00011000, %00011000, %00011000, %00011000, %00011000, %01111000, %00000000 ; ] 29
!byte %00000000, %00000000, %00000000, %00000000, %00000000, %00000000, %00000000, %00000000 ; TODO 30
!byte %00000000, %00000000, %00000000, %00000000, %00000000, %00000000, %00000000, %00000000 ; TODO 31
!byte %00000000, %00000000, %00000000, %00000000, %00000000, %00000000, %00000000, %00000000 ; space 32
!byte %00011000, %00111100, %00111100, %00011000, %00011000, %00000000, %00011000, %00000000 ; ! 33
!byte %01101100, %01101100, %00000000, %00000000, %00000000, %00000000, %00000000, %00000000 ; "" 34
!byte %01101100, %01101100, %11111110, %01101100, %11111110, %01101100, %01101100, %00000000 ; # 35
!byte %00110000, %01111100, %11000000, %01111000, %00001100, %11111000, %00110000, %00000000 ; $ 36
!byte %00000000, %11000110, %11001100, %00011000, %00110000, %01100110, %11000110, %00000000 ; % 37
!byte %00111000, %01101100, %00111000, %01110110, %11011100, %11001100, %01110110, %00000000 ; & 38
!byte %01100000, %01100000, %11000000, %00000000, %00000000, %00000000, %00000000, %00000000 ; ' 39
!byte %00011000, %00110000, %01100000, %01100000, %01100000, %00110000, %00011000, %00000000 ; ( 40
!byte %01100000, %00110000, %00011000, %00011000, %00011000, %00110000, %01100000, %00000000 ; ) 41
!byte %00000000, %01100110, %00111100, %11111111, %00111100, %01100110, %00000000, %00000000 ; * 42
!byte %00000000, %00110000, %00110000, %11111100, %00110000, %00110000, %00000000, %00000000 ; + 43
!byte %00000000, %00000000, %00000000, %00000000, %00000000, %00110000, %00110000, %01100000 ; , 44
!byte %00000000, %00000000, %00000000, %11111100, %00000000, %00000000, %00000000, %00000000 ; - 45
!byte %00000000, %00000000, %00000000, %00000000, %00000000, %00110000, %00110000, %00000000 ; . 46
!byte %00000110, %00001100, %00011000, %00110000, %01100000, %11000000, %10000000, %00000000 ; / 47
!byte %01111100, %11000110, %11001110, %11011110, %11110110, %11100110, %01111100, %00000000 ; 0 48
!byte %00110000, %01110000, %00110000, %00110000, %00110000, %00110000, %11111100, %00000000 ; 1 49
!byte %01111000, %11001100, %00001100, %00111000, %01100000, %11001100, %11111100, %00000000 ; 2 50
!byte %01111000, %11001100, %00001100, %00111000, %00001100, %11001100, %01111000, %00000000 ; 3 51
!byte %00011100, %00111100, %01101100, %11001100, %11111110, %00001100, %00011110, %00000000 ; 4 52
!byte %11111100, %11000000, %11111000, %00001100, %00001100, %11001100, %01111000, %00000000 ; 5 53
!byte %00111000, %01100000, %11000000, %11111000, %11001100, %11001100, %01111000, %00000000 ; 6 54
!byte %11111100, %11001100, %00001100, %00011000, %00110000, %00110000, %00110000, %00000000 ; 7 55
!byte %01111000, %11001100, %11001100, %01111000, %11001100, %11001100, %01111000, %00000000 ; 8 56
!byte %01111000, %11001100, %11001100, %01111100, %00001100, %00011000, %01110000, %00000000 ; 9 57
!byte %00000000, %00110000, %00110000, %00000000, %00000000, %00110000, %00110000, %00000000 ; : 58
!byte %00000000, %00110000, %00110000, %00000000, %00000000, %00110000, %00110000, %01100000 ; ; 59
!byte %00011000, %00110000, %01100000, %11000000, %01100000, %00110000, %00011000, %00000000 ; < 60
!byte %00000000, %00000000, %11111100, %00000000, %00000000, %11111100, %00000000, %00000000 ; = 61
!byte %01100000, %00110000, %00011000, %00001100, %00011000, %00110000, %01100000, %00000000 ; > 62
!byte %00000000, %00000000, %00000000, %00000000, %00000000, %00000000, %00000000, %00000000 ; ? 63
; ==================== end of VERA driver =================
; Zero terminated "string" encoded to use the default VERA font layout
; See: https://cx16.dk/veratext/
my_str:
!byte $03,$0F,$0D,$0D,$01,$0E,$04,$05,$12,$20,$18,$31,$36,$00
; H E L L O , W O R L D !
my_str2:
!byte $20,$08,$05,$0C,$0C,$0F,$2C,$20,$17,$0F,$12,$0C,$04,$21,$20,$00
; since this is a 65c02, we need to define the reset vector
*=$fffc
!word Reset
!word $0000
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