Adding CBM510 support

git-svn-id: svn://svn.cc65.org/cc65/trunk@913 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/cbm510/color.s

@@ -0,0 +1,65 @@
+;
+; Ullrich von Bassewitz, 13.09.2001
+;
+
+ 	.export	    	_textcolor, _bgcolor, _bordercolor
+	.import	    	sys_bank, restore_bank
+	.importzp	vic
+
+	.include    	"zeropage.inc"
+	.include	"io.inc"
+
+
+; ------------------------------------------------------------------------
+; unsigned char __fastcall__ textcolor (unsigned char color);
+; /* Set the color for text output. The old color setting is returned. */
+;
+
+.proc	_textcolor
+
+	ldx	CHARCOLOR	; get old value
+ 	sta	CHARCOLOR	; set new value
+	txa
+	rts
+
+.endproc
+
+; ------------------------------------------------------------------------
+; unsigned char __fastcall__ bgcolor (unsigned char color);
+; /* Set the color for the background. The old color setting is returned. */
+;
+
+.proc   _bgcolor
+
+	jsr	sys_bank		; Switch to the system bank
+	pha	    			; Save new color
+	ldy	#VIC_BG_COLOR0
+	lda	(vic),y	      		; Get current color...
+	tax	    			; ...into X
+	pla	    			; Get new color
+	sta	(vic),y			; Set new color
+	txa	    			; Get old color into X
+	jmp	restore_bank		; Restore the old color
+
+.endproc
+
+; ------------------------------------------------------------------------
+; unsigned char __fastcall__ bordercolor (unsigned char color);
+; /* Set the color for the border. The old color setting is returned. */
+
+.proc	_bordercolor
+
+	jsr	sys_bank		; Switch to the system bank
+	pha				; Save new color
+	ldy	#VIC_BORDERCOLOR
+	lda	(vic),y	      		; Get current color...
+	tax				; ...into X
+	pla				; Get new color
+	sta	(vic),y			; Set new color
+	txa				; Get old color into X
+	jmp	restore_bank		; Restore the old color
+
+.endproc
+
+
+