cc65/libsrc/apple2/cputc.s

95 lines
2.5 KiB
ArmAsm

;
; Ullrich von Bassewitz, 06.08.1998
;
; void __fastcall__ cputcxy (unsigned char x, unsigned char y, char c);
; void __fastcall__ cputc (char c);
;
.ifdef __APPLE2ENH__
.constructor initconio
.endif
.export _cputcxy, _cputc
.export cputdirect, newline, putchar
.import popa, _gotoxy, VTABZ
.include "apple2.inc"
.segment "ONCE"
.ifdef __APPLE2ENH__
initconio:
sta SETALTCHAR ; Switch in alternate charset
bit LORES ; Limit SET80COL-HISCR to text
rts
.endif
.code
; Plot a character - also used as internal function
_cputcxy:
pha ; Save C
jsr popa ; Get Y
jsr _gotoxy
pla ; Restore C
_cputc:
cmp #$0D ; Test for \r = carrage return
beq left
cmp #$0A ; Test for \n = line feed
beq newline
ora #$80 ; Turn on high bit
.ifndef __APPLE2ENH__
cmp #$E0 ; Test for lowercase
bcc cputdirect
and #$DF ; Convert to uppercase
.endif
cputdirect:
jsr putchar
inc CH ; Bump to next column
lda CH
cmp WNDWDTH
bcc :+
left: lda #$00 ; Goto left edge of screen
sta CH
: rts
newline:
inc CV ; Bump to next line
lda CV
cmp WNDBTM
bcc :+
lda WNDTOP ; Goto top of screen
sta CV
: jmp VTABZ
putchar:
.ifdef __APPLE2ENH__
ldy INVFLG
cpy #$FF ; Normal character display mode?
beq put
cmp #$E0 ; Lowercase?
bcc mask
and #$7F ; Inverse lowercase
bra put
.endif
mask: and INVFLG ; Apply normal, inverse, flash
put: ldy CH
.ifdef __APPLE2ENH__
bit RD80VID ; In 80 column mode?
bpl col40 ; No, in 40 cols
pha
tya
lsr ; Div by 2
tay
pla
bcs col40 ; Odd cols go in 40 col memory
bit HISCR ; Assume SET80COL
sta (BASL),Y
bit LOWSCR ; Assume SET80COL
rts
.endif
col40: sta (BASL),Y
rts