Sierra Game Debug modes

AGI GAMES (1984-1989)



AGI GAMES (1984-1989)

Game testers often need some way to achieve certain things quickly so that they can test a certain part of the game. Most AGI games still have the debug code that these testers used when the games were being developed. Of the thirteen AGI games that were made, there are only four which I havn't discovered the debug mode in. Most of the games activate their debug modes by pushing the ALT-D key combination. The other games use a magic phrase to enter the debug mode.

Game Command
Gold Rush: type "bird man".
Kings Quest 3: type "rats ass" (in some versions ALT-D works instead).
Police Quest: type "stink bug".
Space Quest: type "backstage" or "dbg".
type "tester" to bring up Rogers screen coordinates..

The following are standard debug mode commands:
Command Result
TP Teleport to another room.
SHOW PRIORITY Show the current rooms priority bands and control lines.
GET OBJECT Get any inventory item.
GIMME GIMME Get all inventory items.
SHOW FLAG Show one of the 256 flags.
SET FLAG Set one of the 256 flags.
RESET FLAG Clear one of the 256 flags.
SHOW VAR Show one of the 256 variables.
SET VAR Change the value of one of the 256 variables.
POSITION Change egos position.
SHOW POSITION Show egos current screen coordinates.
OBJECT NUMBER Gives a list of all the objects and their object numbers.
OBJECT ROOM Says which room an object is found in.
ROOM Says what room number ego is currently in.
SET PRIORITY Set the priority of ego.
RELEASE PRIORITY Release the last priority that ego was set to.

Of all the AGI games, it is unknown whether the KQ4 256K version, MH1, MH2 and Mixed Up Mother Goose have a debug mode or not. KQ4 will almost certainly have one, while MUMG probably doesn't even though its words.tok file has all the debug words contained in it. Manhunter 2 has some kind of debug mode which allows you to teleport and change variable values because there are text messages in the first LOGIC file along these lines. Manhunter: New York probably has the same debug mode.

If any one has the AGI version of KQ4, contact me be email and I'll tell you how to go about finding out whether it has a debug mode or not.


Created by MB Computing Underground Department.

In Sierra-Online games like a LSL2, LSL3, KQ1 (1990) you can enter Sierra's debug mode by pressing

LSHIFT+RSHIFT+"-" (the numeric keypad minus key). All global variable values can be changed (except Read-only). Changes have effect after exiting DEBUG mode.

Global variables

  Variable Notes
1 Game ID (Eg. kq1 for King's Quest I) Read-only (*)
2 Room number (Eg. rm8 for room #8) Read-only
3 Speed 0 - Max, but 99 is quite slow
4 Unknown  
5-8 Something from EventHandler  
9 Pointer to obj. Inv Read-only
12 Previous scene number  
13 Scene number Can be used for teleport.
14 Breakpoint flag If non-zero, Auto-DEBUG on room CHANGE
15 Score New score is displayed only after next non-DEBUG change.
16 Max Score New score is displayed only after next non-DEBUG change.
30 Pointer to SG Directory. Use INSPECT to view SG directory.

(*) Value changes have no effect. They are automaticaly restored.

SCIV debug commands
Value Command Result
q Quit Quit immediatly
t Temp variable Inspect temp variable
a Inspect acc  
i Inspect See chapter "Inspect"
o Object See available objects.
r Resources See resources
s Send stack  
d Display memory  
f Free heap  
g Global variable Inspect global variable
l Local variable Inspect local variable
b Break in (If object value is changed, Auto-DEBUG)
c Inspect current object  

Inspect subcommands

Value Result
Up, Down, Left, Right Scroll
Enter Next item
[,] Move to address
i Inspect
e Edit
c Collection

If you press C while inspecting Inv, you can get Inventory List Use inspect subcommands recursively. Eg. While viewing Inventory List, assign ego address to owner. ego, owner are objects. So you can collect all treasures at any time. Warning: Write ego in lowercase.

You can inspect hex address of memory (Eg. $3455) or any object (Eg. Sound)

Time 20:45:10
Date 05/28/91
Special thanks to MG & MK
If you have additional information please send it to FIDONET 2:495/13.10
Data phone (0132)942873
Voice (0132)942550


Some SCI games have their own debug modes other than the SHIFT-SHIFT-MINUS mode. Heros Quest and Quest for Glory are two examples. These modes are entered by typing magic phrases as was the case in some of the AGI games. These debug modes are very similar to the AGI ones.


Type "razzle dazzle root beer" The following ALT combinations will then have the following effect.

Command Result
Alt-T Warp. Here are the room numbers for several screens. The rest are forest screens. Some screens don't exist; so if you try them the game will quit. Don't try anything higher than 97 because there ARE no more rooms after that. This is like the AGI "TP" command.
Alt-I Get any Item. Here are all the item numbers and the item it represents. Like the AGI "GET OBJECT" command.
Alt-C / Alt-P Shows the priority bands and control lines. This is like the AGI "SHOW PRIORITY" command.
Alt-M Memory.
Alt-X Changes all character skills to 80.
Alt-B Changes amount of silvers you have. Max number is 9912.
Alt-K Changes skill level. Max skill number is 9912, although 999 is more than enough. Here's a list of skills by number.
Alt-E Picture of ego.
Alt-S All the pictures used on the screen that ARE NOT part of the background or foreground. Essentially, these are just props.


Type "suck blue frog".

Cheat Codes: Hold down the ALT key and press:

*W: Feature Writer (?)

B: Edit money and communication skill

K: Edit one skill-see below for skill lists

H: Edit all skills-sets all skills to designated value

I: Edit inventory items-see below for item list

T: Teleport to certain place or time. See below for place lists.

S: List of sprites on current screen

E: Ego status

P: Shows the priority bands.

F: Displays the memory

*G: Path Maker (?)

Z: Kicks you out to DOS

X: Kicks you out to DOS

C: Shows you where you can move. Control line screen.

V: Turns the effects of ALT-C and ALT-P off. Show Visual screen.

*N: ?

W, G, and N (marked with *) should NOT be touched. (Or says the note that came with these codes).

On the other hand, if you're adventurous like I am and don't mind the consequences should it destroy your game or machine, then I'd suggest having a deeper look at these features because its the only Sierra game I know of which has left them in. I've mucked around with them and managed to add a prop to one of the screens which looked very much like ego (the main character). Obviously it must have been a life sized doll because it wasn't moving and I know that my QFG character doesn't have a twin ;)

In all seriousness now, it appears as if these particular features were used for adding to the game.


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