Difference between revisions of "SCI/Debug Modes"

  This FAQ will explain the several debug modes found in Sierra On-Line adventure games.

  - Any brackets, asterisks or quotation marks should NOT be typed in. They're only used to clarify.

  - Anything between brackets means it's either a key or a combination of keys. So:

  - Words between asterisks should be replaced with a proper word/object/thing. So:

   "PITCH *object name*" means you should type the object you want to get, e.g. "PITCH WIG".

  And while you might know, Sierra games use an "interpreter". This basically is a program/system which translates the program statements (in byte-code) into executable machine code one line at a time as the program is running; as opposed to a compiler, which translates the entire program before the program is executed. The different interpreters used by Sierra for their games are described in the next chapter.

  This FAQ only covers the debug modes of IBM PC versions, however, some of them might work on the other systems too.

  Platform: IBM PC (including PCjr & TANDY), Commodore AMIGA, Atari ST & Apple Macintosh

  Nearly all SCI0 games have an internal debugger, meaning a build-in debugger in the game's interpreter. Next to that, some games also have a script debugger. Like with AGI games, a script debugger is a debug script located directly in the game code itself, rather than in the interpreter's code.

  The internal debugger is activated by pressing [SHIFT + SHIFT + MINUS]. So both SHIFTs and the MINUS key located at the NUMERIC keypad AT ONCE. The debugger is/was mainly useful for programmers, but some things like changing variables can be easily done.

  Example: The room number is controlled by global variable 13. When the debug is activated, push [G]. It will ask which global variable should be changed. Enter "13". Now it will show the current value of the variable. Change this to your preferred, valid room number. Exit the debugger to see the effect.

  The script debugger is a bit more interesting and often more extensive. Not all games have a script debugger, some of them were likely removed before the final release of the game in question. However, a fair amount of games still have it. The script debugger is in most cases activated by typing a certain sentence in the game. This sentence differs from game to game.

  When there isn't a sentence to type, but a debug is present in the game, it can be activated by changing the value of a certain global variable. An example of doing this is given in the previous chapter "Internal Debugger".

  When the script debugger is activated, the following general commands are available:

  To activate the debug mode, type: "overtime nosleep". An extra menu item will be activated on room change.

  Most options are also available in the debug menu item. The menu option "Clicks" will (de-)activate the debug options triggered by mouse.

  There are two ways of activating this debug mode, depending on the version of your copy of the game.

  Although "praise lord" works too in v1.002.000 (the one included in the Leisure Suit Larry collections), it offers another method. At the copy-protection sequence at the start of the game, a phone number is asked. Enter "555-0724" to pass the copy-protection and get the debug mode activated.

  To activate the debug mode, type: "ascot backdrop". The debug mode will be activated when entering a new room.

  * Before this will work, you'll have to place the SCI picture resource of the room you want to test in the game directory and rename it to "PIC.999". That specific picture/room will be shown and can be tested in the game.

  Also, the self-running demo of LSL3 has the same debug mode, apart from a room-selector on the beginning. It can be activated by extracting SCRIPT.000 from the RESOURCE files (the easiest way being SCI DECODER v1.0) and in addition changing the byte at offset 0x00000064 to "00" (instead of the original "01"). Beware that it's not really worth it, since it's pretty much the same deal and lots of missing resources cause it to crash easily.

  Since the input is disabled, use the internal debugger to change the value of global variable 100 to 1.

  A useless (but interesting for some nonetheless) debug menu is still partly in the game's scripts. It can be activated by extracting SCRIPT.000 from the RESOURCE files (the easiest way being SCI DECODER v1.0) and in addition changing the byte at offset 0x000026C7 to "01" (instead of the original "00"). This will activate the debug mode at the start of the game, which will also initialize the extra pulldown menu's.

  Police Quest 2 should respond to the sentence: "kiss angel 187", but somehow it doesn't work. So use the internal debugger to change the value of global variable 101 to 1.

  SCI1 is a whole different story. The internal debugger has been removed from pretty much every (public) release of the games. You can still use the key combination [SHIFT + SHIFT + MINUS], but it will throw you out of the game, due to the absence of the debugger. That said, internal SCI1 debuggers are not non-existant (really early versions, like the interpreter used with "Jones in the Fast Lane" still have their debugger) and work just like the SCI0 ones.

  However, script debuggers have survived in a bunch of games. The way of activating them depends mainly on the version of the SCI interpreter.

SCI1 games (interpreter version < 1.001.000) do not have a standard way of activating the script debugger (atleast, I haven't found one yet).

  SCI11 games (interpreter versions > 1.001.000) are activated by extracting the debug script from the packed RESOURCE files. Some kind of routine checks if the file is present in the game directory (and not just in the RESOURCE files) and the debug mode gets activated. An empty file won't do the trick, since the external scripts override the ones in the packed resource.

  Since the SCI1 internal debugger is pretty much the same as the one found in the SCI0 games, refer to chapter 4.1 on its usage. Currently, the following SCI1 games with an internal debugger are known:

  Sometimes an interpreter can be swapped with another one, to use within other games, but often the games get too buggy to play. As of yet, trail-and-error is the key here.

  Rename/remove the file "version" in your PQ3 directory, or set the attribute to "read-only".

  This will give you some options at the beginning to configure which flags should be set and where/when you will start the game.

  Somewhere in 1991, the cracking group The Humble Guys released a beta version of Space Quest 4. I suspect it had version number 1.052 (I found some saves of the beta), but the first sales release had that too, so far for that lead.

  However, someone named "Beamer" typed up a list back then describing the functions and based on that, I made this following list:

  ** Seems like either Sierra or the author of the original text file swapped the keys for "Show cast" and "Show ego information"

  At the time of writing, VAG's SCIResDump can be used for games using an interpreter > 1.001.000. This is a bit tricky, but beats any other manual method. Refer to its documentation on further use. When dumping the files, it would be advisable to dump, apart from the SCR file, the accompanying HEP and TEX file. Some debug modes will not work properly without them.

  Besides giving you the usual debug options, some games will give the "Where to?" dialog. Basically, this is a dialog giving you the opportuninty to set various flags/variables at the beginning of the game, so you can for example start halfway in the game or so.

  This debug mode however, is partially removed or something. Only the "Where to?" room select dialog on start will appear, the rest of the keys won't work.

  The "magic" script is 10. However, this script cannot be found in the English release of Freddy Pharkas. Extract 10.SCR/10.HEP/10.TEX from the RESOURCE.MSG file (instead of the usual RESOURCE.000) in a NON-ENGLISH(!) release. I've tested this with the German, Spanish and French release. The extracted script will work with every version of the game, also the English one.

  The "magic" script is 911. Extract 911.SCR/911.HEP/911.TEX. Besides giving you a "Where to?" dialog at the beginning, it activates the following options:

  The "magic" script is 899. Extract 899.SCR/899.HEP/899.TEX. To activate the debug mode in this case, they should be first renamed to 702.SCR/702.HEP/702.TEX.

  The "magic" script is 298. However, it's not available anymore in the game's resource files. So to activate the debug mode, debug scripts from another game should be used. You can use the script from either Laura Bow 2 or Police Quest (SCI remake). They should be first renamed to 298.SCR/298.HEP/298.TEX.

  Now the "Where to?" dialog works, while the remaining functions don't. Perhaps the scripts used are not fully compatible with this game.

  The Space Quest series seem to be the major victim of leaked betas at Sierra. A Space Quest 5 beta version was released by some group, back in 1993. This beta was actually a reviewer's copy, included a script debugger (but no internal debugger) and works just like most of them.

  This probably is the buggiest debug mode, thus not really interesting. What is somewhat interesting though, is that the "magic" script (10), cannot be found in the game's resource files, yet, the script somehow turned up on the web. So download it and copy 10.SCR/10.HEP/10.TEX to the game directory.

  In the beginning, SCI32 games had the same activation procedure as SCI11 games. In this FAQ, this will be called the "Traditional" method. However, at a certain point, this procedure got replaced by the so-called "CLASSES" method. Both are explained below.

  There is currently one SCI32 interpreter known with an internal debugger. It's bundled with a rare Gabriel Knight 2 demo and can be activated by pushing the [`] key, usually above [TAB].

  This particular interpreter also support the following command line parameters:

  The "Traditional" method is the same method as the SCI11 one: It relies on extracting scripts from the RESOURCE or RESMAP file. Again, at the time of writing, VAG's SCIResDump is the tool to use. Please refer to its documention on further use.

  This isn't exactly the "traditional" method, but it does involve external scripts. Activate the debug mode by renaming/removing 4.SCR

  The later SCI32 games (1995-1997) use the "CLASSES" method. They depend on a file in the game directory, called "CLASSES". This can be an empty file. It's checked on existance by some code in the script, if found, the debug mode gets activated. "AUTOTP" as an empty file will function too sometimes, however its purpose is not fully clear to me.

  Activate the debug mode usings the "CLASSES" method. Besides giving you a "Where to?" dialog at the beginning, it activates the following options:

  There are some more debug/tester functions in this game. They can be accessed by teleporting to room 98. This will activate "The Elite Tester V1.0":

  Activate the debug mode usings the "CLASSES" method and when in the game, press both SHIFTs and the PLUS key located at the NUMERIC keypad AT ONCE. It activates the following options:

  Activate the debug mode usings the "CLASSES" method. Besides giving you a "Where to?" dialog at the beginning, it activates the following options:

  One game (currently) hasn't got the usual debug mode. Nevertheless, it's not really an "easter egg" either, so this section was created.

  This game has no real debug mode (anymore), but yet it had some leftovers of one, which were actually worth to mention. Trigger certain actions by clicking 4 times with the "hand icon" on the following list of objects:

  Plant above elevator  -  Shablee has the gown and gives Larry the condom and champagne

  Towel rack  -  Gives the towel, toilet cover, toilet paper, hand creme, brochure and the wash cloth.

  Right sculpture  -  Gives the swim suit, your room key and the inflatable beaver

  When clicking 4 times on the big tree, to activate the "Shablee sequence", somehow the debug mode gets activated (sort of), because the game will react to key combinations used in debug. However, being removed, it will terminate the game directly with the error "cannot find 911.hep". Also, clicking 4 times will be reduced to 2 times.

  The following games have some references to debug options, yet no way found to activate them, if they can be activated at all: