Let's begin by opening the Hornet data file. These exercises assume that you'll be using the full game data file, results with the demo file will be slightly different. Push the 'Open' button and locate the file. After that, select the Hawaii 1 scenario from the pop-up menu and push the 'Read Data' button.
You end up with 7 cards, each describing one object. There are 3 FA18's, a DC10, a JEEP, a TNKR and a UH60 helicopter.
FA18 number 0, on the first card, is you. You are supposed to do most of your flying yourself, so you get the shortest script of all the planes and only very few waypoints. Most of the script in the demo is to provide you with weapons, the script in the full game is even shorter.
The script consists of commands that have a one byte opcode (command code) and zero or more parameters. Let's have a look at the actual FA18 script. The first command is '0C' with one parameter '15'. To my shame I must admit that I have yet to find out it's purpose. Although practically every script in the data file starts with it, I haven't noticed any obvious effects yet. Probably it's something very trivial that I've missed.
I do know what the other commands are for, though! the '0D 01' places you with the good guys. Change this to '0D 00' and everyone will consider you to be on the Iraqi side. In the Arizona missions this determines whether you are in the Red or the Blue team.
The '11 00' command places you at waypoint 0. This is the only command that your script absolutely needs! Leave it out and your plane will be at 0,0,0 coordinates which leaves you dead in the water (literally.) Exercise: how do you place the plane at waypoint 1?
The '15 00' points you north. The 00 represents the heading in tens of degrees. 180 degrees is '12'. Hexadecimal, remember?
In the demo file you would now find the '0E' command, which provides your plane with weapons. If you are using the full game data file, you have to look at another scenario to see an example. Any entries you have here will override your weapons choice in the game. The opcode is followed by 10 bytes, which actually is a string of capital letters. You may have seen such strings in weapons patches. Each letter (byte) determines a weapon at one of the wing positions. (This part of the script would have looked better in plain text instead of hexadecimal. Remember that 41 is 'A', 42 is 'B', etc.)
Finally, there is the 'E8' command which signals the end of the script. Not all scripts end with E8, some end with a '3A xx' command, causing the program to loop back to byte xx of the script. See the JEEP for an example. Apparently if you leave it out, nothing bad happens since all the padding zero bytes are NOPs (No operation.)
All in all not very spectacular, isn't it? What the script does is place you at waypoint 0, heading north and perhaps with a load of weapons. You might want to change a few things now and try to see their effects. (Push the 'Write Data' button to actually write your changes to the file. Use mission 1 of the training missions.) '1509', for instance, will rotate your plane 90 degrees and will let you face your wingman. While you're at it, change the plane type on the third card, i.e. FA18 number 2, to MG23 number 0. You're now looking a baddy right in the face.
Time for a more elaborate script. Press the Clear Scenario button and then Read the Scenario 'Not a DC10'. Believe me when I tell you that this is the script of the DC10 of the training scenario, but with the plane type changed to FA18 so that you are in control. Write it to the data file. Now start the game but don't touch that dial!
Without you doing anything your plane will start and taxi to the runway to take off. It will do some sightseeing in the neighborhood and eventually after a few minutes it will return and land. Immediately the cycle will then start over.
Notice the A/P light? Some autopilot, isn't it? Press 2 to select the lower instruments and watch how your machine goes from waypoint to waypoint. You can press M to see your flight plan on the map. If you want to take control simply press A to switch off the magic autopilot. This does not guarantee full control over the plane, though, sometimes the autopilot kicks in again for some prescheduled task.
How did the autopilot perform it's flight? Let's have a look at the script. Try to figure it out with the help of the reference at the end of this tutorial and write it down in plain text. Now run the mission again.
I'm not going to take you through all the steps in the flight. There are some noteworthy things, though. Notice the difference between taxiing and flying towards a waypoint. With taxiing your speed will remain under 50, whereas with the 1C command your speed is not limited. Ground vehicles should use 1C. Also note that you should only initiate an automatic landing sequence when you are downwind from the runway. As with a normal ILS landing, the autopilot will direct the plane towards the glide slope which happens to be underground when you are upwind. Here again, try and change a few things and see what it does. And notice that just like you the DC10 also has to ask for clearance from the tower and that your autopilot responds to it.
Next step is combining several objects into one scenario. Load "The MiG and Me". Don't look at the scenario yet, simply write it to the datafile and run it. You are on runway 36R and there is a MiG on 36L. Of course you're supposed to shoot the MiG which shouldn't be too difficult. The MiG will not fight back. Remember to contact the tower first, by the way. After having shot it continue your left turn towards Pearl Harbor and see what happens.
Did you really run the scenario? No? Then you're not allowed to read on. Go back. We'll wait.
... boring musical intermezzo...
As you may have noticed there actually were three objects in this scenario. By now you should have no problems understanding the scripts for the FA18 and the MiG. But who launched those missiles? Have a look at the third card. Yes, there's the nasty m.... Don't worry, you'll have full control over it in a minute. Basically you use the same commands for the ground weapons and vehicles as for the planes, although your SAMS will not fly (at least not the launchers.) Note the '0D 00' command. That's why it targeted you. If the MiG would have survived it would have had no trouble landing at Pearl Harbor. But wait, wasn't the SAM intended to protect the airfield from the bad guys? And you're a good guy, aren't you? Change the '0D' command and run the scenario again. This time, don't shoot the MiG but let it continue it's course to Pearl Harbor. That's more like it.
There is a major difference here between the demo and the real game. In the demo you'll get a 'Threat' warning right after take off and you have a good chance of being shot at right away. The '0F' command that determines how aggressive the SAM site is was apparently retuned for the game. In the demo you have very little chance against even moderately aggressive SAMS.
The rest is up to you. Start playing around with existing scenario's first. Try to figure out what they do and make small or large modifications. Remember that not everything is under script control. There are SAM sites around airfields in every scenario, that appear to be part of the scenery. Also there are for instance the small nuclear bomb proof mining buildings. In the training missions the carrier is not under script control. This may be disappointing for demo users because they will not be able to run the carrier scenarios. Well, that's what the real game is for, isn't it? And then there are some objects that escape normal script control for some other reason, such as the BLDGs that do not have waypoints but that surely exist in the scenario.
What follows is the reference for the scripting language as far as I understand it now. As I mentioned in the ReadMe, part of this is borrowed from the "A Basic Lesson, Hrnt Data" file from frontacs@indigo.ie. These parts are marked accordingly. For the rest you will notice a lot of gaps. There is no reason not to believe that most of the opcodes from let's say '0C' to '3A' should be used for something. (Read that again to get the double negation.) Post your findings if you can fill the gaps.
Oh, and one other thing. As you already may know you can fly any scenario and plane of your choice in the Kuwait missions. Select 'Tour of Duty' with the option key down and you'll get a dialog box where you can enter the mission number and a plane type. If the scenario has more planes of the same type you'll get the one with number zero. If you'd rather try another, well, who's going to stop you if you swap them in the scenario? And if you change the first MiG in the first Kuwait scenario to DC10 you'll have your DC10 in Basra. You may try to fly it to Baghdad, of course, but perhaps it's more fun to change it's Friend-or-Foe and see if you can escape to friendly surroundings. Have fun.
Scripting Reference:
Every command has one opcode byte, optionally followed by a fixed number of parameters.
0Cxx: ?? not clear. Appears to have no effect on the planes at all. According to (1) it may be used for the score, although it's also used in the training missions.
0Dxx: Chooses sides. xx=00 or xx=01 in the missions. I don't know if you can have even more sides to complicate things.
0E 'string': Select weapons load. Is followed by a string of 10 characters, each of which selects a weapon for placement at a wing position. Characters are from 'A' to 'U'
0Fxx: Aggressiveness. According to (1) useful values seem to range from 0 to 6.
11xx: Place object at waypoint xx
12xxyy: According to (1) this picks a random waypoint from xx to yy.
13xx: Place object at altitude xx
14'string': string is an object name. Possibly used for targeting moving objects. To be explored.
15xx: Set heading of object to xx in tens of degrees. 00 is north
17xx. This possibly chooses from a fixed library of waypoints. Used for placing buildings. To be explored.
19xx: Taxi to waypoint xx.
1A: Take off and fly to altitude 1500 feet. By immediately following this with a 20xx command, you can select a different altitude.
1Cxx: Fly or go (ground vehicles) to waypoint xx
1Dxxyy: Select the waypoint range xx to yy as targets
1Exx: Go to heading xx (again in tens of degrees)
20xx: Go to altitude xx in thousands of feet
21xxyy: Random Altitude from xx*1000 to yy*1000 feet
22xx: Thrust to xx%
230x: Afterburner stage (max 6, of course)
24: Invoke automatic landing procedure
25xx: Brakes. 01 is on. 00 is off.
26xx: Hook. 01 is on, 00 is off.
27xx: Radar. 01 is on, 00 is off. Makes you or others visible on their radar.
28xx: Arm and launch weapon xx, where xx is the character that identifies the weapon (see '0E' command)
2C: Come to a complete stop and lock the brakes.
2Dxx: According to (1) this will schedule something to happen before the end of another task. The value of xx is not completely clear to me (seconds before arrival?). In combination with the 28xx command it does influence the moment where the weapon is actually launched in training mission 5. This might be a good place to experiment.
2Fxx: Delay xx seconds.
31xx: Delay xx minutes
34: ??
38: Wait for clearance ("hold for traffic")
3Axx: Loop back to byte xx (first byte in the script is number 0)
E8: End of script
Any reference to (1) in the above points to article "A Basic Lesson, Hrnt Data ╥by frontacs@indigo.ie
Both this file and his two scenario's "173rd Airborne" and "Long Reach" can be found at the Hornet Archive.
