fix bug in Alu1 related to zero-storage boxes

diff --git a/ships/Alu1.ship b/ships/Alu1.ship
index 2a5019e..6818560 100644 (file)
--- a/ships/Alu1.ship
+++ b/ships/Alu1.ship
@@ -18,7 +18,7 @@ ABS:
 == TeX ==============================================================
 == Fleeterpreter ====================================================
     public void service() {
-        if (box_in.dataReadyForShip() && box_inOp.dataReadyForShip()) {
+        if (box_in.dataReadyForShip() && box_inOp.dataReadyForShip() && box_out.readyForDataFromShip()) {
             long data   = box_in.removeDataForShip();
             long opcode = box_inOp.removeDataForShip();
             switch((int)opcode) {