Gamescape

Latest revision as of 00:02, 27 January 2019

Gamescape is an interactive fiction authoring system, made by "Drew Software" (apparently a single person, "Dennis Drew"^[1]) for DOS, developed from 1988^[2] to ca. 1993. Users edit games as plain text files, and these are then "compiled" with a program called GSCAPE.EXE into a format that can be interpreted by a program called SCAPERUN.EXE.

Gamescape had the ability to display its own format of graphics files along with games. Reference is made to "sound and music"^[3], however, little information is available on this.

[edit] Extensions

Editor files, which are editable plaintext, have the extension .ADV. However, this is not a fixed convention, as "include" files (which are inserted into an .ADV file at compile time) have the extensions "IN1", "IN2", "IN3", etc.^[4] (It is unclear whether this convention was used, in practice, outside of the sample files.)

"Compiled" files appear have the extensions "GS1", "GS2", etc. (These will henceforth be referred to collectively as "GS?" files.) These have only been observed going up to 6, and it is not unreasonable (see #Identification) that this is a hard limit.

[edit] Versions

In a version released 1991, neither the help files (INSTRUCT.DOC and GSCAPE.DOC) nor the message presented when GSCAPE.EXE is run reference a "lite" version^[4], only "registered" and "unregistered" versions, where the "unregistered" version has a full interpreter but not a full compiler^[5]. However, as of 1993, Gamescape divided itself into "Gamescape Lite" ("economy version, character graphics") and "Gamescape Graphic" ("high-res color graphics, advanced commands"), and an "unregistered" version, a reduced-functionality version of "Gamescape Graphic", which claims to have a limit of 10 days legal use (but apparently no mechanism to enforce this beyond the honor system).^[6]

Version numbers are used oddly - version 3.4, for example, was "[a]vailable to registered users only", and an extant copy identifies itself as version "A.3".^[7]

[edit] "Linked" Files

References are made in extant files to a "MSGFL command" that provides "common message file access"^[8]. This feature is only available in the "registered" version.

[edit] Identification

.ADV (and IN? files, which use the same format) have no well-defined beginning, but are ASCII files, and will almost certainly contain the strings ">LOCAT", ">MESSG", and ">WORDS"^[9].

[edit] Compiled Files

.GS? files are difficult to identify. Although there are some commonalities between games (for example, .GS5 always seems to contain many 0x17 bytes, though not necessarily at the same position), with the exception of GS1 (to be described shortly), there is no clear pattern to them; none have apparently consistent start byes, none contain meaningful text strings, and some are sometimes 0 bytes in length, without any easily evident pattern.

.GS1 files, however, have a consistent structure. They are ASCII files, consisting of:

• Lines consisting of integers in base 10, none of which have been seen to exceed 999, and a very large amount of which are "501"
• Lines consisting of similar integers, but preceded by a single space character
• Lines consisting only of a single space character

Some .GS? files contain the graphics files.

It would be useful to anyone seeking to precisely identify the format to look at the disassembler in #Links.

[edit] Software

• version A.3, from 1993
• Gamescape Graphic, C.4, 1993
• Gamescape Lite, unknown version, possibly broken
• another copy of Gamescape C.4, 1993
• A QuickBASIC dissassembler

[edit] Sample Files

• https://www.ifarchive.org/if-archive/games/pc/nobeer.zip

[edit] Links

• The Interactive Fiction Wiki entry for Gamescape
• contains the manual, with some sections removed, as "GSCAPE.DOC"

[edit] References

1. ↑ https://www.ifarchive.org/if-archive/programming/gamescape/gscape.zip, INSTRUCT.DOC
2. ↑ https://archive.org/details/GamescapeGraphic_1020, INSTRUCT.DOC
3. ↑ https://archive.org/details/msdos_Gamescape_1993, message upon running GSCAPE.EXE
4. ↑ ^{4.0 4.1} https://www.ifarchive.org/if-archive/programming/gamescape/gscape.zip
5. ↑ Running GSCAPE.EXE from https://www.ifarchive.org/if-archive/programming/gamescape/gscape.zip
6. ↑ Running GSCAPE.EXE from https://archive.org/details/GamescapeGraphic_1020
7. ↑ https://www.ifarchive.org/if-archive/programming/gamescape/gscape.zip, GSCAPE.DOC, section "CHANGES TO GAMESCAPE"
8. ↑ https://www.ifarchive.org/if-archive/programming/gamescape/gscape.zip, GSCAPE.DOC, section "CHANGES TO GAMESCAPE", 3.1
9. ↑ https://www.ifarchive.org/if-archive/programming/gamescape/gscape.zip, GSCAPE.DOC, section "SEGMENTS"