initial import, completely untested, does not compile yet

libsrc/pcengine/cputc.s

@@ -0,0 +1,117 @@
+;
+; 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
+	.import		popa, _gotoxy
+        .import         PLOT
+
+		.importzp tmp3,tmp4
+
+	.include	"pcengine.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 #$0d 		; CR?
+    	bne	L1
+    	lda	#0
+    	sta	CURS_X
+       	beq    	plot		; Recalculate pointers
+
+L1: 	cmp	#$0a  	  	; LF?
+       	beq	newline		; Recalculate pointers
+
+; Printable char of some sort
+
+cputdirect:
+  	jsr	putchar		; Write the character to the screen
+
+; Advance cursor position
+
+advance:
+	ldy	CURS_X
+   	iny
+   	cpy	#xsize
+   	bne	L3
+	jsr	newline		; new line
+   	ldy	#0    	  	; + cr
+L3:	sty	CURS_X
+	jmp plot
+   	;rts
+
+newline:
+;   	lda	#xsize
+;   	clc
+;   	adc	SCREEN_PTR
+;   	sta	SCREEN_PTR
+;   	bcc	L4
+;   	inc	SCREEN_PTR+1
+;;   	clc
+;L4:;	lda #xsize
+ ;  	adc	CRAM_PTR
+ ;  	sta	CRAM_PTR
+ ;  	bcc	L5
+  ; 	inc	CRAM_PTR+1
+;L5:
+	
+	inc	CURS_Y
+
+;    jmp plot
+;   	rts
+
+; 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:
+
+    	ora	RVS             ; Set revers bit
+
+		tax
+
+        st0     #VDC_MAWR    ; Memory Adress Write
+
+		lda SCREEN_PTR
+		staio VDC_DATA_LO
+
+		lda SCREEN_PTR+1
+		staio VDC_DATA_HI
+
+		st0     #VDC_VWR    ; VWR
+
+		txa
+		staio VDC_DATA_LO   ; character
+
+		;;st2     #$32      ; attrib ?!
+		lda   CHARCOLOR
+		
+		;;lda #2
+		asl a
+		asl a
+		asl a
+		asl a
+
+		and #$f0
+        ora   #$02
+		staio VDC_DATA_HI
+
+        rts