initial support for internal MEGA65 DOS

src/dos_m65/dos_vectable.s

@@ -0,0 +1,40 @@
+
+// A vector table to integrate DOS with the MEGA65 Kernal
+
+.word dos_INIT
+.word dos_HASUNIT
+.word dos_ACPTR
+.word dos_CIOUT
+.word dos_LISTEN
+.word dos_SECOND
+.word dos_TALK
+.word dos_TKSA
+.word dos_UNTLK
+.word dos_UNLSN
+
+
+// Dummy implementations - XXX to be replaced with real ones
+
+dos_INIT:
+	nop
+dos_HASUNIT:
+	nop
+dos_ACPTR:
+	nop
+dos_CIOUT:
+	nop
+dos_LISTEN:
+	nop
+dos_SECOND:
+	nop
+dos_TALK:
+	nop
+dos_TKSA:
+	nop
+dos_UNTLK:
+	nop
+dos_UNLSN:
+	nop
+
+	sec
+	rts