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cc65/libsrc/cbm610/cputc.s
cuz 37178d5141 Make screensize() fetch the values dynamically instead of using variables
that are set on startup. This is needed to support the C128, which can switch
the screen size at runtime.


git-svn-id: svn://svn.cc65.org/cc65/trunk@2042 b7a2c559-68d2-44c3-8de9-860c34a00d81
2003-04-09 19:34:57 +00:00

103 lines
1.8 KiB
ArmAsm

;
; Ullrich von Bassewitz, 06.08.1998
;
; void cputcxy (unsigned char x, unsigned char y, char c);
; void cputc (char c);
;
.export _cputcxy, _cputc, cputdirect, putchar
.export newline, plot
.exportzp CURS_X, CURS_Y
.import PLOT
.import _gotoxy
.import popa
.include "cbm610.inc"
_cputcxy:
pha ; Save C
jsr popa ; Get Y
jsr _gotoxy ; Set cursor, drop x
pla ; Restore C
; Plot a character - also used as internal function
_cputc: cmp #$0A ; CR?
bne L1
lda #0
sta CURS_X
beq plot ; Recalculate pointers
L1: cmp #$0D ; LF?
beq newline ; Recalculate pointers
; Printable char of some sort
cmp #' '
bcc cputdirect ; Other control char
tay
bmi L10
cmp #$60
bcc L2
and #$DF
bne cputdirect ; Branch always
L2: and #$3F
cputdirect:
jsr putchar ; Write the character to the screen
; Advance cursor position
advance:
iny
cpy #XSIZE
bne L3
jsr newline ; new line
ldy #0 ; + cr
L3: sty CURS_X
rts
newline:
clc
lda #XSIZE
adc CharPtr
sta CharPtr
bcc L4
inc CharPtr+1
L4: inc CURS_Y
rts
; Handle character if high bit set
L10: and #$7F
cmp #$7E ; PI?
bne L11
lda #$5E ; Load screen code for PI
bne cputdirect
L11: ora #$40
bne cputdirect ; Branch always
; Set cursor position, calculate RAM pointers
plot: ldy CURS_X
ldx CURS_Y
clc
jmp PLOT
; Write one character to the screen without doing anything else, return X
; position in Y
putchar:
ldx IndReg
ldy #$0F
sty IndReg
ora RVS ; Set revers bit
ldy CURS_X
sta (CharPtr),y ; Set char
stx IndReg
rts