IN/OUT Z80 instructions implemented

src/zvm_m65/zvm_banking.s

@@ -124,6 +124,20 @@ ZVM_set_bank_1:
 
 	rts
 
+ZVM_fetch_IO:
+
+	; XXX fetch addresses via ADDR_IO - but which ones are safe? Should we have a whitelist?
+	lda #$00
+	sta REG_A
+	rts
+
+ZVM_store_IO:
+
+	; XXX again, we should have a whitelist of addresses
+	rts
+
+
+
 ZVM_fetch_opcode_bank_0:
 
 	; XXX implement, should return byte in .A