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cc65/libsrc/apple2/cputc.s
Colin Leroy-Mira 8a140e6503 Conio: 65c02 optimisations
cputc: -2 cycles per char, -2 cycles per carriage return
cputs: -5 cycles per char, -3 cycles on cputsxy
vcprintf: -6 cycles per char
2023-09-02 12:44:53 +02:00

107 lines
2.9 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, putchardirect
.import gotoxy, VTABZ
.include "apple2.inc"
.macpack cpu
.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 gotoxy ; Call this one, will pop params
pla ; Restore C and run into _cputc
_cputc:
cmp #$0D ; Test for \r = carrage return
beq left
cmp #$0A ; Test for \n = line feed
beq newline
eor #$80 ; Invert high bit
.ifndef __APPLE2ENH__
cmp #$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 :+
jsr newline
left:
.if (.cpu .bitand CPU_ISET_65SC02)
stz CH ; Goto left edge of screen
.else
lda #$00 ; Goto left edge of screen
sta CH
.endif
: rts
newline:
inc CV ; Bump to next line
lda CV
cmp WNDBTM
bcc :+
lda WNDTOP ; Goto top of screen
sta CV
: jmp VTABZ
putchar:
.ifdef __APPLE2ENH__
ldy INVFLG
cpy #$FF ; Normal character display mode?
beq putchardirect
cmp #$E0 ; Lowercase?
bcc mask
and #$7F ; Inverse lowercase
bra putchardirect
.endif
mask: and INVFLG ; Apply normal, inverse, flash
putchardirect:
pha
.ifdef __APPLE2ENH__
lda CH
bit RD80VID ; In 80 column mode?
bpl put ; No, just go ahead
lsr ; Div by 2
bcs put ; Odd cols go in main memory
bit HISCR ; Assume SET80COL
put: tay
.else
ldy CH
.endif
lda (BASL),Y ; Get current character
tax ; Return old character for _cgetc
pla
sta (BASL),Y
.ifdef __APPLE2ENH__
bit LOWSCR ; Doesn't hurt in 40 column mode
.endif
rts