Design change: Do keyboard polling internally without calling the kernal

in the system bank. For one this performs better (several %), second it
allows to handle the function keys in conformance with other platforms.
Without the custom keyboard routine, we would have to apply some more
magic to the function keys to make them work as with other cc65 targets.


git-svn-id: svn://svn.cc65.org/cc65/trunk@2811 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/cbm610/kbhit.s

@@ -1,23 +1,16 @@
 ;
-; Ullrich von Bassewitz, 2003-12-20
+; Ullrich von Bassewitz, 06.08.1998
 ;
 ; int kbhit (void);
 ;
 
 	.export		_kbhit
-
-        .importzp       sysp0
 	.import		return0, return1
+        .import         keyidx: zp
 
-	.include	"cbm610.inc"
 
 .proc	_kbhit
-        ldx     IndReg
-        lda     #$0F
-        sta     IndReg
-        ldy     #$D1            ; Number of keys in kbd buffer
-        lda     (sysp0),y
-        stx     IndReg
+	lda	keyidx          ; Get number of characters
 	bne   	L1
 	jmp	return0
 L1:	jmp	return1