Porting the original: DOS, C64, and the road to Amiga/Atari ST
How the 1985 game spread across home computers in its first few years, and why Amiga and Atari ST owners had to wait.
1985–1986: the first wave
MS-DOS got Where in the World Is Carmen Sandiego? the same year as the Apple II original, in 1985. A Commodore 64 conversion followed in 1986. Archival copies of all three credit Brøderbund itself as both developer and publisher; no separate third-party porting studio is documented in the surviving records for these early conversions, which was typical of Brøderbund's in-house approach in this period.
What changed, what didn't
The C64 and DOS versions carried over the same structure as the Apple II release: three witness stops per city, the same clue logic, the same rank ladder. The visible differences were mostly cosmetic — the C64's SID chip gave witness interactions a different sound, and DOS machines with CGA cards displayed the same graphics in a different palette than the Apple II's native modes. None of the early ports changed the underlying game.
Where Amiga and Atari ST fit in
Amiga and Atari ST owners did not get the plain 1985 game at all. Both platforms entered the lineup later, and only as part of the upgraded Enhanced Edition — Amiga in 1989, Atari ST not until 1991. That's a detail worth knowing if you're trying to date a secondhand disk: an Amiga copy of "Where in the World" is, by definition, the VGA-and-mouse Enhanced build, not a straight port of the original menu-driven game.
Apple's own line kept going too
Brøderbund also carried the game onto the enhanced Apple IIGS, again through the Enhanced line rather than as a separate IIe-style port. Between the original Apple II/DOS/C64 releases and the later Enhanced wave, the game reached nearly every home computer a mid-1980s classroom or living room was likely to own.