As hardware began to advance beyond what AGI could utilize, Sierra began development on its next engine, SCript Interpreter or later Sierra Creative Interpreter (SCI). A year before the last official AGI game, Manhunter 2: San Francisco in 1989, Sierra released the first SCI (SCI0) game, King's Quest IV: The Perils of Rosella in 1988. In keeping with Moore's Law, SCI could take advantage of the constantly increasing capabilities of the new hardware. As with AGI in its day, SCI was a big leap forward in technology. SCI's 200px x 320px vector graphics allowed for noticeably better graphics over AGI's 160px x 200px. While still just 16 colors, but SCI0 introduced dithering, which mixed pixels of different colors into the same fill areas that gave the effect of more than 16 colors. See the Differences Between Sierra's AGI and SCI Engines.
KQ4AGI Fisherman's Shack
KQ4SCI Fisherman's Shack
Sound
SCI introduced support for the new sound cards. This expanded its audio capabilities over that of AGI's three voice with noise channel sound PCjr/Tandy sound. With the advent of SCI, music became an inseparable part of Sierra games. Even though the first exposure most had was with AdLib's hoots and honks, it also supported the MPU-401, which allowed Sierra's composers to create some amazing Roland MT-32 sound tracks. KQ4's MT-32 track gave a quality to the game's music that at the time was unsurpassed.
KQ4AGI Intro
KQ4SCI Intro
KQ4AGI Dwarves's Mine
KQ4SCI Dwarves's Mine
Requirements
MS-DOS
Minimum CPU:
Intel 8088 / 8086 8mhz
Minimum RAM:
512 KB
Graphics Modes:
Hercules, CGA, EGA, VGA
Audio Hardware:
PC Speaker, Tandy/PCjr Sound, AdLib, Roland MT-32, Sound Blaster, IBM Music Feature Card
Note that the first version of the game did not recognize resources outside of the resource archive. This made patching the game more difficult as new resource patches cannot simply be dropped into the game's folder. To be accessible to the game the patch needs to be packed and mapped in the game's resource volume to be accessible to the game.
This new installer includes a Munt enabled build of DOSBox for MT-32 sound. It requires that the "MT32_CONTROL.ROM" and "MT32_PCM.ROM" ROMs be present on installation. Requires files from the original distribution media.
This installer not only includes the Munt enabled build of DOSBox for MT-32 sound, but also adds sounds from the Amiga versions with a patch by NewRisingSun. Requires files from the original distribution media.
Debug Modes
Internal Debugger
The internal debugger can be activated at any point during the game by simultaneously pressing [SHIFT + SHIFT + MINUS] (the MINUS key located at the NUMERIC keypad). The debugger is/was mainly useful for programmers, but some things like changing variables can be easily done. To exit this mode, press Shift and D.
The following options are available:
Command
Action
Q
Quit game
B
Set Breakpoint
A
Inspect ID in accumulator
C
Inspect Current Set of Objects
Press C to see all of the objects within that set. Press I to inspect the selector. Press E to edit that selector.
I
Inspect Object/Memory
Press cursor Up/Down to go up/down through the memory by 16 bytes and Left/Right
to go up/down the memory by 2 bytes.
F
Show free heap
S
Show sends
R
Show resource types
O
Show objects in heap
[SHIFT + O]
Show objects with addresses
[SHIFT + S]
Show stack usage
G
Change global variable
L
Change local variable
T
Change temp variable
ENTER
Proceed single step through script.
TAB
Step across send
[SHIFT + /]
Help; shows list (incomplete) of shortcuts.
Note that these are case sensitive, so [CAPS LOCK] should be deactivated.
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 ([SHIFT + SHIFT + MINUS] or [SHIFT + SHIFT + D]) to see the effect.
In-Game Debugger
To activate the debug mode, type: "overtime nosleep". An extra menu item will be activated on room change.