mirror of
https://github.com/cc65/cc65.git
synced 2024-12-25 02:29:52 +00:00
99 lines
2.3 KiB
ArmAsm
99 lines
2.3 KiB
ArmAsm
;
|
|
; 2020-10-13, Greg King
|
|
;
|
|
; void __fastcall__ cputcxy (unsigned char x, unsigned char y, char c);
|
|
; void __fastcall__ cputc (char c);
|
|
;
|
|
|
|
.export _cputcxy, _cputc, cputdirect, putchar
|
|
.export newline, plot
|
|
|
|
.import gotoxy, PLOT
|
|
|
|
.include "cx16.inc"
|
|
|
|
|
|
; Move to a cursor position, then print a character.
|
|
|
|
_cputcxy:
|
|
pha ; Save C
|
|
jsr gotoxy ; Set cursor, drop x and y
|
|
pla
|
|
|
|
; Print a character -- also used as an internal function.
|
|
|
|
_cputc: cmp #$0D ; X16 '\n'?
|
|
beq newline
|
|
cmp #$0A ; X16 '\r'?
|
|
beq cr
|
|
|
|
; Printable char. of some sort.
|
|
; Convert it from PetSCII into a screen-code.
|
|
|
|
convert:
|
|
tay
|
|
lsr a ; Divide by 256/8
|
|
lsr a
|
|
lsr a
|
|
lsr a
|
|
lsr a
|
|
tax ; .X = %00000xxx
|
|
tya
|
|
eor pet_to_screen,x
|
|
|
|
cputdirect:
|
|
jsr putchar ; Write character to screen, return .Y
|
|
|
|
; Advance the cursor position.
|
|
|
|
iny
|
|
cpy LLEN ; Reached end of line?
|
|
bne L3
|
|
jsr newline ; Wrap around
|
|
|
|
cr: ldy #$00
|
|
L3: sty CURS_X
|
|
rts
|
|
|
|
; Move down.
|
|
|
|
newline:
|
|
inc SCREEN_PTR+1
|
|
inc CURS_Y
|
|
rts
|
|
|
|
|
|
; Set the cursor's position, calculate RAM pointer.
|
|
|
|
plot: ldy CURS_X
|
|
ldx CURS_Y
|
|
clc
|
|
jmp PLOT ; Set the new cursor
|
|
|
|
|
|
; Write one screen-code and color to the video RAM without doing anything else.
|
|
; Return the x position in .Y .
|
|
|
|
putchar:
|
|
ora RVS ; Set revers bit
|
|
tax
|
|
stz VERA::CTRL ; Use port 0
|
|
lda CURS_Y
|
|
sta VERA::ADDR+1 ; Set row number
|
|
lda #VERA::INC1 ; Address increments by one
|
|
sta VERA::ADDR+2
|
|
ldy CURS_X ; Get character column into .Y
|
|
tya
|
|
asl a ; Each character has two bytes
|
|
sta VERA::ADDR
|
|
stx VERA::DATA0
|
|
lda CHARCOLOR
|
|
sta VERA::DATA0
|
|
rts
|
|
|
|
|
|
.rodata
|
|
pet_to_screen:
|
|
.byte %10000000,%00000000,%01000000,%00100000 ; PetSCII -> screen-code
|
|
.byte %01000000,%11000000,%10000000,%10000000
|