Added condes IRQ routines and a README file.

Made k_blncur a condes IRQ routine and moved it to cgetc.s.
Added mouse and joystick routines.


git-svn-id: svn://svn.cc65.org/cc65/trunk@951 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/cbm510/readjoy.s

@@ -0,0 +1,62 @@
+;
+; Ullrich von Bassewitz, 23.09.1998
+;
+; unsigned readjoy (unsigned char joy);
+;
+
+     	.export		_readjoy
+	.import		sys_bank, restore_bank
+	.importzp	cia2, tmp1
+
+	.include	"io.inc"
+
+; ------------------------------------------------------------------------
+; unsigned __fastcall__ readjoy (unsigned char joy);
+
+
+.proc	_readjoy
+
+	jsr	sys_bank    	; Switch to the system bank
+       	tax			; Save joystick number
+
+; Get the direction bits
+
+	ldy	#CIA_PRB
+	lda	(cia2),y    	; Read joystick inputs
+	sta	tmp1
+
+; Get the fire bits
+
+        ldy     #CIA_PRA
+	lda	(cia2),y
+
+; Make the result value
+
+	cpx	#$00	    	; Joystick 0?
+	bne	@L1 	    	; Jump if no
+
+; Joystick 1, fire is in bit 6, direction in bit 0-3
+
+  	asl     a
+	jmp	@L2
+
+; Joystick 2, fire is in bit 7, direction in bit 5-7
+
+@L1:    ldy     #$00  	     	; High byte of return value
+	lsr     tmp1
+	lsr	tmp1
+	lsr	tmp1
+       	lsr	tmp1
+
+; Mask the relavant bits, get the fire bit
+
+@L2:	asl	a		; Fire bit into carry
+	lda	tmp1
+	and	#$0F
+    	bcc	@L3
+    	ora	#$10
+@L3:	eor	#$1F		; All bits are inverted
+	jmp	restore_bank
+
+.endproc
+