imported CHRIN from UP9600 driver

c64/kernal/rs232/chrin_rs232_up2400.s

@@ -1,14 +1,14 @@
 
 //
-// RS-232 part of the CHKRIN routine
+// RS-232 part of the CHRIN routine
 //
 
 
-#if HAS_RS232
+#if CONFIG_RS232_UP2400
 
 
 chrin_rs232:
 	STUB_IMPLEMENTATION() // XXX provide implementation for both UP2400 and UP9600
 
 
-#endif // HAS_RS232
+#endif // CONFIG_RS232_UP2400

c64/kernal/rs232/chrin_rs232_up9600.s

@@ -0,0 +1,43 @@
+
+//
+// RS-232 part of the CHRIN routine
+//
+
+// Based on UP9600 code by Daniel Dallman with Bo Zimmerman adaptations
+
+
+#if CONFIG_RS232_UP9600
+
+
+chrin_rs232:
+
+	phy_trash_a
+	phx_trash_a
+
+	lda #$00
+	sta XXX_SAVBYTE
+    sta RSSTAT
+	jsr XXX_RSIN
+    bcc !+
+	plx_trash_a
+	ply_trash_a
+	
+	lda #$08    // XXX don't we have some routine for this?
+	sta RSSTAT
+    lda #$00
+    clc
+    rts
+!:
+	sta XXX_SAVBYTE
+
+XXX_DOGET4:
+
+	plx_trash_a
+	ply_trash_a
+
+	lda XXX_SAVBYTE
+	clc
+	rts
+
+
+#endif // CONFIG_RS232_UP9600