DOS Days

Sierra Creative Interpreter (SCI)

Recognising the aging limitations of AGI, in 1987 Sierra began working on a successor with higher-resolution graphics, better sound and enhanced features. The new game engine was called SCI, or "SCript Interpreter", and later stood for "Sierra Creative Interpreter".

It used a new object-oriented language to replace AGI's procedural language. This allowed it far more flexibility in what an SCI game could do with much more complex logic.

The first title to be written using SCI was King's Quest IV: The Perils of Rosella, and used what they called SCI0. Both an AGI and SCI version of this game were produced, as SCI required a more powerful PC to run well and Sierra didn't want to limit their customer base for the new game to the few who had a faster PC. The SCI version was the only one directly sold in stores but if a purchaser discovered their machine wasn't up to spec they could send in their SCI version to Sierra to receive the AGI version as a replacement.

Just as with AGI, the SCI interpreter was developed not only for the IBM PC and Tandy/PCjr, but also for other platforms. SCI was ported to Apple Macintosh, Commodore Amiga, Atari ST, and FM Towns. In addition, all early SCI titles (SCI0 and SCI1) came with both 5.25" and 3.5" floppy diskettes. From SCI1.1 and SCI2, only 3.5" floppy diskettes were supplied. The really late titles came on CD-ROM.

SCI0 (1988-1989)

Though SCI0 still only supported a maximum of 16 colours (with a resolution of 640 x 400), it did add dithering which made games appear to use many more colours than a 16-colour palette would normally show. More crucially was the sound support which now extended to Ad Lib, and Roland MT-32.

The primary visual differences between AGI and SCI to the consumer were the replacement of the text parser with icon-driven actions such as look, walk, talk to, use, etc., and a standard resolution of 640 x 400.


AGI version (left), and SCI version (right)


SCI1 (1989-1990)

SCI1 arrived in late 1989. The main upgrade over SCI0 was its support of 256-colour VGA graphics. The resolution remained at 640 x 400. The first SCI1 game to be released was King's Quest V: Absence Makes the Heart Go Yonder. Also between SCI0 and SCI1, Sierra implemented digital audio drivers, allowing speech in their adventures for the first time. The first game which supported speech was Space Quest III: The Pirates of Pestulon.


(From top-left clockwise): King's Quest V: Absence Makes the Heart Go Yonder,
Leisure Suit Larry 3: Passionate Patti, Jones in the Fast Lane
and Space Quest IV: Roger Wilco and the Time Rippers

You can see which SCI version was used for each game in this table:

Game Year AGI Version Notes*
King's Quest IV: The Perils or Rosella 1988 SCI0 Interpreter versions 0.000.247, 0.000.274, 0.000.409, and 0.000.502
Xmas Card 1988 1988 SCI0 Interpreter version 0.000.294
Leisure Suit Larry 2: Looking for Love in Several Wrong Places 1988 SCI0 Interpreter versions 0.000.343 and 0.000.409
Police Quest 2: The Vengeance 1988 SCI0 Interpreter versions 0.000.397, 0.000.409 and 0.000.490
Space Quest III: The Pirates of Pestulon 1989 SCI0 Interpreter versions 0.000.453, 0.000.685 and S.old.114
Astro Chicken 1989 SCI0 Interpreter version 0.000.453
Fun Seekers Guide 1989 SCI0 Interpreter version 0.000.506
Hoyle's Book of Games 1 1989 SCI0 Interpreter versions 0.000.509 and 0.000.530
Leisure Suit Larry 3: Passionate Patti and the Pulsating Pectorals 1989 SCI0 Interpreter versions 0.000.530, 0.000.572, S.old.114 and S.old.123
Hero's Quest 1990 SCI0 Interpreter versions 0.000.566 and 0.000.629
Quest for Glory 1 1990 SCI0 Interpreter version 0.000.629
The Colonel's Bequest (Laura Bow 1) 1990 SCI0 Interpreter version 0.000.631
Codename: ICEMAN 1990 SCI0 Interpreter versions 0.000.668 and 0.000.685
Mixed-Up Mother Goose 1990 SCI0 Interpreter version 0.000.685
King's Quest I: Quest for the Crown (remake) 1990 SCI0 Interpreter version S.old.010
Jones in the Fast Lane 1991 SCI1 Interpreter version x.yyy.yyy
Quest for Glory II 1991 SCI1 Interpreter versions 0.001.026, 1.000.041, 1.000.072 and 1.000.087
Xmas Card 1990 1990 SCI1 Interpreter versions 1.000.172 and 1.000.174
Castle of Dr. Brain 1991 SCI1 Interpreter versions 1.000.005, 1.000.044, 1.000.066 and 1.000.068
King's Quest V: Absence Makes the Heart Go Yonder 1991 SCI1 Interpreter versions 1.000.058, 1.000.060, 1.000.073 and 1.000.784
Leisure Suit Larry 1 (VGA remake) 1991 SCI1 Interpreter versions 1.000.084, 1.000.510, 1.000.575 and 1.000.577
Space Quest I (VGA remake) 1991 SCI1 Interpreter version 1.000.181
Mixed Up Fairy Tales 1991 SCI1 Interpreter versions 1.000.145 and 1.000.158
Conquests of the Longbow 1991 SCI1 Interpreter versions 1.000.168, 1.000.169, 1.000.175 and 1.000.181
Leisure Suit Larry 5 1991 SCI1 Interpreter versions 1.000.181, 1.LS5.006, 1.LS5.019, T.A00.159 and T.A00.169.
Space Quest IV: Roger Wilco and the Time Rippers 199x SCI1 Interpreter versions 1.000.744, 1.000.753 and 1.SQ4.057
Police Quest III: The Kindred 1993 SCI1 Interpreter version 1.pq3.018, 1.pq3.021, T.A00.052 and T.A00.178
Hoyle's Card Games 3 1993 SCI1 Interpreter version x.yyy.yyy

*Numerous minor interpreter versions were created, usually to fix bugs in earlier versions.

 

SCI Tools

In May 1999 Brian Provinciano began writing SCI Studio, a complete SCI game creation tool. This was hosted on his website, BriPro.com which is now offline, It creates SCI0 games which are in 16 colours but the latest version 3.0 also includes rudimentary support for SCI1.1 and SCI32. The main SCI Studio was supported by several utilities (also from Brian), including SCI Graphic Studio (latest version 1.50) and SCI Script Compiler (latest version 0.98) which ran as a DOS command-line tool or Windows 95-XP tool. Several versions of SCI Studio exist:



Clockwise from top-left: SCI Studio's resource explorer, vocabulary editor,
script IDE and picture editor

Another SCI game creation tool is SCI Companion, written by Phil Fortier (Troflip). This supports the creation and editing of SCI0 and SCI1.1 (EGA and VGA) games. You can download SCI Companion here:

Here are some other SCI tools:

  • SCI Decoder (EGA/VGA) - a resource viewer that runs in DOS. Written by Carl Muckenhoupt.
  • CSR - a DOS utility that compresses SCI resources. Written by AsP.
  • SCI Packer - a DOS utility that packs SCI0 resources into one resource, decreasing their size. Written by Dark Fiber.
  • SCI0 Resource Manager - a Win32 utility that extracts and manages SCI0 resources. Written by Ravi.
  • SoundBox v1.0 - editor for SCI0 sound resources. It can convert format 0 and format 1 MIDI files and allows managing resource specific features like sound cues. The source code is also available. You may need the statically-linked binary here too.
  • Anvil Studio - a free Windows 98-7 audio creation/editing tool to sequence and play music with your MIDI equipment. Can be used to create SCI game music and sound effects.
  • VMD Player v0.5b - plays Sierra's .VMD videos

And finally, here are some third-party video and audio drivers that work with Sierra SCI titles:

  • Plantronics ColorPlus - An SCI0 driver by Benedikt Freisen that provides a 320x200 16-colour mode. Includes full mouse cursor support and 8088 compatibility. Copy the file to the game's directory and run INSTALL. Source code is here.
  • Sigma Designs Color 400 - An SCI0 driver by Benedikt Freisen that provides a 320x200 16-colour mode. Includes full mouse cursor support and 8088 compatibility. Copy the file to the game's directory and run INSTALL. Source code is here.
  • Amstrad PC1512 - Updated Amstrad Alph Graphics Colour VDU Controller driver.
  • Updated CGA driver
  • Updated Disney Sound Source driver
  • Ravi's General MIDI Driver v0.5.1 BETA - This SCI0 game driver uses a bastardized version of Rickard Lind's patch mapping algorithm, taken from the FreeSCI project, to map instruments in the MT-32 track from each game their GM equivalents. Compatible with Leisure Suit Larry 2, 3, Police Quest 2, Space Quest 3, King's Quest IV, Quest for Glory I (EGA), The Colonel's Bequest, Code-Name: ICEMAN, and Conquest of Camelot