Add blinking cursor on input

git-svn-id: svn://svn.cc65.org/cc65/trunk@944 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/cbm510/cgetc.s

@@ -1,11 +1,10 @@
 ;
-; Ullrich von Bassewitz, 06.08.1998
+; Ullrich von Bassewitz, 16.09.2001
 ;
 ; char cgetc (void);
 ;
 
 	.export	   	_cgetc
-	.import	   	plot, write_crtc
 	.import	   	cursor
 
 	.include   	"zeropage.inc"
@@ -16,23 +15,81 @@
 
 .proc	_cgetc
 
-L1:    	lda	KeyIndex
-       	beq	L1
+    	lda	KeyIndex		; Characters waiting?
+       	bne    	L3			; Jump if so
 
-L2:    	ldx    	#$00		; Get index
-       	ldy	KeyBuf		; Get first character in the buffer
-       	sei
-L3:    	lda	KeyBuf+1,x	; Move up the remaining chars
-       	sta	KeyBuf,x
+; Switch on the cursor if needed
+
+  	lda	CURS_FLAG
+  	pha
+  	lda	cursor
+  	jsr	setcursor
+L1:	lda	KeyIndex
+  	beq	L1
+  	ldx	#0
+    	pla
+ 	bne	L2
        	inx
-       	cpx	KeyIndex
-       	bne	L3
-       	dec	KeyIndex
+L2:    	txa
+       	jsr	setcursor
+
+; Read the character from the keyboard buffer
+
+L3:    	ldx    	#$00		; Get index
+       	ldy    	KeyBuf		; Get first character in the buffer
+       	sei
+L4:    	lda    	KeyBuf+1,x	; Move up the remaining chars
+       	sta    	KeyBuf,x
+       	inx
+       	cpx    	KeyIndex
+       	bne    	L4
+       	dec    	KeyIndex
        	cli
 
-       	ldx	#$00		; High byte
-       	tya			; First char from buffer
+       	ldx    	#$00		; High byte
+       	tya    			; First char from buffer
        	rts
 
 .endproc
 
+; ------------------------------------------------------------------------
+;
+
+.proc	setcursor
+
+	ldy	#$00		       	;
+       	tax			       	; On or off?
+       	bne    	@L9		       	; Go set it on
+    	lda	CURS_FLAG	       	; Is the cursor currently off?
+       	bne    	@L8			; Jump if yes
+    	lda	#1
+    	sta	CURS_FLAG		; Mark it as off
+    	lda	CURS_STATE		; Cursor currently displayed?
+	sty	CURS_STATE		; Cursor will be cleared later
+       	beq    	@L8			; Jump if no
+
+; Switch to the system bank, load Y with the cursor X coordinate
+
+	lda	#$0F
+	sta	IndReg	   	       	; Access system bank
+	ldy	CURS_X
+
+; Reset the current cursor
+
+     	lda    	CURS_COLOR
+	sta	(CRAM_PTR),y	       	; Store cursor color
+      	lda	ExecReg
+      	sta	IndReg 		       	; Switch to our segment
+      	lda	(SCREEN_PTR),y
+      	eor	#$80	      	       	; Toggle reverse flag
+      	sta	(SCREEN_PTR),y
+
+; Done
+
+@L8:  	rts
+
+@L9: 	sty	CURS_FLAG	       	; Cursor on (Y = 0)
+	rts
+
+.endproc
+