$OpenBSD$

This needs to return something.

Index: tools/fuzix6303emu/main.c
--- tools/fuzix6303emu/main.c.orig
+++ tools/fuzix6303emu/main.c
@@ -63,7 +63,7 @@ void m6800_port_output(struct m6800 *cpu, int port)
 {}
 
 uint8_t m6800_port_input(struct m6800 *cpu, int port)
-{}
+{ return 0; }
 
 void showregs(void)
 {
