In September 1994 Shaun Southern of Magnetic Fields, the team behind Gremlin’s Lotus racing games, told The One that he did not think “it would be possible to do something like Doom on the Amiga”. The problem was the way the Amiga stored its screen. To write a bit of data to the screen, he explained, “you have to write one byte on the PC, but on an Amiga you have to write eight.” id Software never released Doom for the Amiga. Four years later Amiga owners had it anyway. id released the game’s source code in December 1997, and by February 1998 The Amiga Informer knew of four Amiga ports already.
That is a homebrew port: a game converted by fans, not its publisher, for a machine the publisher passed over. Some, like the Amiga Doom, were built from released code. Others were rewritten from nothing, by people who studied the original and reproduced it. A third kind now runs the other way: new games written by small teams that ship on a decades-old console as well as on modern ones.
Fast facts
- What it is: an unofficial conversion of a game to a platform it was not released on, made by fans or small independent developers.
- Three routes: porting released source code; rewriting a game from scratch by studying it; building a new game so it runs on old hardware as well as new.
- Legal position: a port that copies a game’s code, art or characters without permission infringes copyright, however old the game. Released source code under a licence, or the rights holder’s blessing, changes that. See Game Clone Legality and Abandonware.
From released code: Doom on the Amiga
The Amiga ports of Doom show what released code made possible. Peter McGavin’s ADoom, Amazing Computing reported in November 1998, “arose after the Linux source code was released to the public in late December ’97”, and had since gained an overlay map, a choice of screen modes, graphics card support, CD32 joypad support and network play. It needed AmigaOS 3.0 and 4MB of fast RAM, and a fast 68030 processor to play in a full-sized window. The magazine judged it “every bit as sleek as the PC version”. A rival port, Doom Attack, was slightly faster but crashed more. id relicensed the code under the GNU General Public License in 1999, and hundreds of other ports followed (the Doom entry has the details).
Rewritten from scratch
Without source code, a port means reproducing a game by watching it. In 1996 two French programmers, Olivier Zardini and Antoine Vignau, working as Brutal Deluxe, wrote LemminGS, a version of Psygnosis’s Lemmings for the Apple IIGS, one of the machines whose owners, Retro Gamer wrote, “refused to accept Apple’s decisions” and kept writing software for it. Retro Gamer noted that it was “never sold commercially”: they gave it away to buyers of their graphics program, Convert 3200.
A rewritten port still copies the original’s characters, graphics and level designs, and a rights holder can object. In April 2019 a programmer known as ZeroPaige released Super Mario Bros. 64, a recreation of Nintendo’s NES game for the Commodore 64 that had taken seven years. Wireframe called it “an impressive recreation of the NES original for Commodore’s computer”. Nintendo sent copyright takedown notices, and the port was removed from legitimate download sites within days of its 18 April release.
New games for old machines
The Sega Dreamcast shows the third route. Sega stopped making the console in 2001, but in 2019 Wireframe found “a hardcore group of developers” still writing for it: games burned to CD would play on most unmodified Dreamcasts, and “one of the pluses of the Dreamcast”, one developer said, “is how easy it is to develop for”. Roel van Mastbergen of Senile Team was making Intrepid Izzy, a puzzle platformer for the PC, PS4 and Dreamcast. “I started this project with only the PC in mind,” he said, but he wrote code with low CPU and RAM requirements “by force of habit”, and when he tried it on the Dreamcast it “ran almost perfectly on the first try”. The Dreamcast audience, he said, put up most of the game’s crowdfunding. Another publisher, JoshProd, released a mix of new games and ports of classic ones, Wireframe noted, “with the blessing of the original developers where they can get it”.
Handhelds had their own scene while they were still on sale. In 2005 Retro Gamer described “the vibrant GBA home-brew scene” on the Game Boy Advance. Commercial publishers had filled the shelves with remakes and arcade compilations, but “many thousands of much-loved titles will never make it to the hand-held. This is where home-brew steps in to fill the void.” Ports of simple games were commonplace, the magazine found, because hobbyists tended to tire of long projects. Jim Bagley’s conversion of Bruce Lee kept “the Speccy version’s insanely playable gameplay”. The programmer known as Quirky had converted Mike Singleton’s Lords of Midnight and Doomdark’s Revenge, and remade the Freescape game Castle Master to run at 15 frames a second, “about four times the speed of the versions on the C64 and Spectrum”. And a group called The Lemoners had reworked Trailblazer, the 8-bit ball-rolling game by Shaun Southern, the programmer who had doubted that the Amiga could run Doom. Others wrote emulators, which ran old games on the new handheld instead of converting them. “For me GBA emulators aren’t about preservation,” one of their authors, Fredrik Olsson, told the magazine. “I just want to play these games on the go!”
Sources
- The One issue 72, September 1994: interview with Magnetic Fields (Shaun Southern on Doom and the Amiga’s screen).
- The Amiga Informer issue 12, February 1998, news: Doom’s source code released and four Amiga ports.
- Amazing Computing vol. 13 no. 11, November 1998: ADoom and Doom Attack (features, requirements, comparison).
- Retro Gamer issue 10, 2004: Apple IIGS feature (LemminGS by Olivier Zardini and Antoine Vignau as Brutal Deluxe, 1996, given away with Convert 3200).
- “Talking with Brutal Deluxe”, Open Apple podcast, 30 April 2012 (web, secondary): Brutal Deluxe as the makers of LemminGS. https://www.open-apple.net/2012/04/30/brutal-deluxe
- Wireframe issue 13, May 2019, p. 15: “Mario C64 no more” (Super Mario Bros. 64, ZeroPaige, seven years, the takedown after the 18 April release).
- Bradly Shankar, “Nintendo issues DMCA takedown for Super Mario Bros. Commodore 64 port”, MobileSyrup, 23 April 2019 (web, secondary): the takedown notice and the sites that removed the port. https://mobilesyrup.com/2019/04/23/nintendo-dmca-takedown-super-mario-bros-commodore-64/
- Robin Wilde, “Dream on: Inside the Dreamcast’s homebrew scene”, Wireframe issue 7, February 2019, pp. 44–47: Senile Team and Intrepid Izzy, Roel van Mastbergen’s quotations, CD-R games on unmodified consoles, JoshProd.
- Retro Gamer issue 20, 2005, from p. 98: the Game Boy Advance home-brew scene (Jim Bagley’s Bruce Lee; Quirky’s conversions and Castle Master; The Lemoners’ Trailblazer) and the interview with Fredrik Olsson.
- Doom’s source release and licence: see the reviewed Doom entry and its sources.