The game was simultaneously produced and published in the AGI and SCI engines. The AGI engine was used in all earlier Sierra adventure games, the SCI in all later ones. SCI supported higher-resolution graphics (320×200 resolution versus 160×200), more sophisticated animation, mouse, and sound card support. Some older features like CGA composite mode and PCjr support were removed. Memory requirements for SCI games were thus double those of AGI games (512 kB vs 256k). The new engine was designed for then-current IBM-compatible hardware (i.e. 8–16 MHz 286 or 386 machines with EGA or VGA graphics and a hard disk) and ran poorly on older 8086 computers. The game was previewed at the Consumer Electronics Show on June 4, 1988.