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;
; Ullrich von Bassewitz, 2000-08-06, 2002-12-21
; Using lots of code from MagerValp, MagerValp@cling.gu.se
;
; void cputcxy (unsigned char x, unsigned char y, char c);
; void cputc (char c);
;
.export _cputcxy, _cputc, cputdirect, putchar
.export newline, plot
.import gotoxy
.include "cbm_kernal.inc"
.include "c128.inc"
newline = NEWLINE
;--------------------------------------------------------------------------
.code
_cputcxy:
pha ; Save C
jsr gotoxy ; Set cursor, drop x and y
pla ; Restore C
; Plot a character - also used as internal function
_cputc: cmp #$0A ; CR?
beq cr ; Output a cr
cmp #$0D ; LF?
bne L2
jmp NEWLINE ; Update cursor position
; Printable char of some sort
L2: cmp #' '
bcc cputdirect ; Other control char
tay
bmi L5
cmp #$60
bcc L3
and #$DF
bne cputdirect ; Branch always
L3: and #$3F
; Output one character to the screen. We will disable scrolling while doing so
cputdirect:
tax ; Save output char
lda SCROLL
pha ; Save scroll flag
lda #$C0
sta SCROLL ; Disable scrolling
txa ; Restore output char
jsr PRINT
pla
sta SCROLL ; Restore old scroll flag
rts
; Handle character if high bit set
L5: and #$7F
cmp #$7E ; PI?
bne L6
lda #$5E ; Load screen code for PI
bne cputdirect
L6: ora #$40
bne cputdirect ; Branch always
; Carriage return
cr: lda #0
sta CURS_X
; Set cursor position, calculate RAM pointers
plot: ldy CURS_X
ldx CURS_Y
clc
jmp PLOT ; Set the new cursor
; Write one character to the screen without doing anything else, return X
; position in Y
putchar = $CC2F
|
