RASPBERRY PI

FeatureEXTRA LIVESINTERVIEWBare-metal DoomFirst-year students at Imperial College Londonhave produced a bare-metal partial clone of Doomfor the first-generation Raspberry Pi in 9,800 lines(see hackaday.com/tag/bare-metal). Csongor Kisstells us more about it…MagPi: Where did the idea come from?Csongor Kiss: As part of our first-year project,we were challenged to make whatever we could,limited by the constraint that it had to work on aRaspberry Pi, and be coded in bare-metal assembly.It turned out to be not so large a constraint.MagPi: What did the Pi bring to the table?Csongor Kiss: The Pi is more powerful than themachines running games like Doom on release,which let us use a higher screen resolution andbetter-quality textures than those of the original.MagPi: What was the process of makingthe conversion?Csongor Kiss: The only thing sourced from theoriginal game were the textures. Everything elsewas built from scratch. We used the Doom wiki forinspiration for things like level design and gameplay,but coded it from the ground up, just as you wouldfor any other project.PORTING A COIN-OPMany arcade games were ported to home computers andconsoles. Things didn’t always go according to plan, however,as Ste Pickford, who worked on Ghosts ‘n Goblins, recalls.“I was given a pile of photographs taken from the screen of thearcade machine by the publisher, Elite, and asked to ‘do thegraphics’ from that. I had no sense of the layout of the levelsor anything. So I went to Stockport arcade with a sketchbookand stood next to its Ghosts ‘n Goblins machine, watchingpeople playing, and sketching the level from what I was seeing.People kept dying and starting over, but I had a decent sketchof the first level and needed someone to get to level two, buteventually the arcade owner spotted me and accused me of‘ripping off his machines’. I was barred.“Programmer Nigel Alderton arranged to drive me to Elite’soffices in Walsall to play their machine instead. It had beenset to free play with infinite continues, but it took us hours andhours to get to the end. We finished around 5am and drovehome to Stockport. But I was only 15 at the time, and it hadn’toccurred to me to phone home. My parents were frantic andon the verge of reporting me as a missing person. Still, I hadthe level layouts, so everything was fine.”StatsDeveloper: id SoftwareReleased: 1999Formats: Windows, Linux, OS X,Dreamcast, PS2Genre: First-person shooterIf you love Doom, you’ll adoreQuake III Arena. It’s a frantic,no‐nonsense first-person arcadeshooter which runs well on the Pi,pitting players against 30 artificialintelligence bots in a game thateschews a plot in favour of all-outfun. The design is deliberatelyminimalist, yet it looks amazingand it plays at a fast speed, givinggamers a good choice of weapons- check out the rocket launchers,shotguns, and the melting plasmagun – while thinking about easeof movement around the playingarea. Accelerator Pads and BounceARCADEBest of the arcadeStanding for “Multiple ArcadeMachine Emulator”, MAME is a wayof playing a host of coin-op arcadegames, many of which were seenas cutting-edge in their day…Street Fighter II:The World WarriorWhen Street Fighter II was releasedinto the arcades in 1991, it sparkeda huge boom in fighting games. Notonly did it truly establish some wellknownvirtual fighters, includingRyu, Chun-Li, and Guile, this deeplystrategic title also showed theimportance in giving players specialmoves unique to each character.Pads take the place of lifts andladders, enabling a greater levelof fluidity in the action.One of the game’s designers,Graeme Devine says he is thrilledthe Pi has the power to open upQuake III to a new audience. “Ihave a Pi sitting right here on mydesk,” he tells us. “It dizzies methat something so small can do somuch, and the fact that people canlook through the Quake III sourcejust opens up so much possibilityall over the world. It feels like thegames industry can explode again.”Metal SlugFor those who love run-and-gunplatfomers, the Metal Slug seriesis nigh on perfect. The original hasstood the test of time, giving playerscontrol of an eight-way joystick andletting them loose on six levels ofshooting, bombing, and jumping.The game, whilebasic in premise,helped to establishthe Neo Geo MVSarcade platform.Ghosts ‘n GoblinsCapcom’s Ghosts ‘n Goblins serieswas a very hard and yet rewardinggame, thanks to impeccable leveldesign that makes it fun to play,regardless of how many times youare nobbled. Players assumed therole of a knight called Arthur in azombie-strewnland, and youonly neededtwo hits tolose a life.42 August 2015raspberrypi.org/magpi