Lecture 2: History of Video Gaming Hardware: The 2-D Era!Prof. Aaron Lanterman!School of Electrical and Computer Engineering!Georgia Institute of Technology!2!Atari 2600 VCS (1977)!• ≈ 1 MHz MOS 6507!– low-cost version of 6502!• 128 bytes RAM!• First ROM cartridges 2K, later 4K!• Discontinued 1992!• Retro releases now on the market!!Pics & info from Wikipedia!Adventure!Solaris!3!Atari 2600 Hardware Tricks!• Could put RAM on the cartridge !– “Atari Super Chip”!– 128 more bytes!!– Jr. Pac-Man!• “Bank switching” to put more ROM on cartridge!– Only 4K immediately addressable - game still has to operate within individual 4K chunks at a time !– Mr. Do!’s Castle (8K), Road Runner (16K, 1989)!– Fatal Run (only 32K game released, 1990)!Info & pics from AtariAge!4!Atari 2600 Hardware Tricks!• “M Network” games!– Atari 2600 games produced by Mattel!– Controversial decision within Mattel!– Done by same group that designed the Intellivision: APh Technology Consulting!• Super Charger added 2K RAM!– Originally planned as a hardware add-ons!– Public didn’t seem to like add-ons, so built in separately into each cartridge!– BurgerTime: Cleverness beats hardware!!Info & pic from www.intellivisionlives.com/bluesky/games/credits/atari1.shtml!www.intellivisionlives.com/bluesky/games/credits/atari2.shtml!5!Atari 2600 - The Chess Story (1)!• “Atari never intended to create a Chess game for the Atari 2600”!• “the original VCS box had a chess piece on it, and Atari was ultimately sued by someone in Florida due to the lack of an actual chess game”!• “Some time later Atari's engineers began working on a version of Chess for the 2600”!Quotes from AtariAge page on Video Chess!6!Atari 2600 - The Chess Story (2)!• “Although Video Chess ended up shipping as a 4K game, earlier versions of the game were larger…This prompted Atari to invent bank-switching ROMs which would be used in later titles that needed more than 4K…”!Quotes & pics from AtariAge page on Video Chess!7!Atari 2600 Graphics!• Custom “Television Interface Adapter” for handling graphics and sound!• No graphics buffer!!• “Playfield” scanline 40 blocks wide, two colors!• Atart 2600 games have intricate timing loop!– For each scanline, program has 76 cycles to do whatever computations it needs to do to load a scanline’s worth of pixels into the TIA (“racing the beam”)!– Have to do most the “game logic” during the vertical blanking period!• Two sprite “players”: 8-“pixel” wide chunks, twice resolution of playfield, could be two colors different than playfield!• Missiles: single-bit!Info from “Chris Crawford on Game Design”!Some details from Ian Bogost!8!Atari 2600 - Graphics Tricks!• Could change TIA registers to change colors!– …from scan line to scan line!– …if you were extremely careful with your timing, you could do it in the middle of a scan line!!• Multiplex a single sprite between multiple objects!– Flickering ghosts in Pac-Mac man!• Flicker varies depending on number of ghosts in play!• Programmers learned to exploit “undocumented features” in the hardware!– Makes the Atari 2600 one of the hardest machines to emulate accurately!9!Rise of the third party developers!• Atari programmers unhappy!– No credit!– Salaried; little if any royalties!• Four top programmers split and form Activision (1979)!– Responsible for over half of Atari’s titles!– Promoted game creators along with games!– Drew top talent!– Breakthrough product: Pitfall! (1982)!– Didn’t pay royalties to Atari!• Nintendo learned from this! !– Atari sued!– Settled in 1982!• Mattel and Coleco made the same mistakes in handling their programmers that Atari did!!10!Intellivision vs. Atari!• Plimpton Sports!– http://www.youtube.com/watch/v/IDza6eTXGEY!• Major League Baseball!– http://www.youtube.com/watch/v/Y0KTjpaG3cg!• Star Strike!– http://www.youtube.com/watch/v/VPB3H_a234s!Photo and info from Wikipedia!11!Mattel Intellivision (1979)!• ≈1 MHz General Instrument CP1610 (16-bit!)!• 1352 bytes RAM:!– 240x8 scratchpad memory!– 352x16 system memory!• 240 words for character buffer – what characters are where and what color!– 512x8 graphics memory!• Character patterns!• 7168 bytes ROM!– 4096x10 (5120) executive ROM!– 2048x8 graphics ROM!Photo and info from Wikipedia!12!Mattel Intellivision - Graphics!• 160x196, 16 colors!• 8 sprites!– 8x8 or 8x16!– Stretching: horizontal (1x, 2x) or vertical (1x, 2x, 4x, 8x)!– Mirroring: horizontal and vertical!– Collision detection: sprite to sprite, sprite to background, sprite to screen border!– Priority: in front of or behind background!Photo and info from Wikipedia!13!Mattel Intellivision - Retro!14!Mattel Intellivision - Modern Homebrew Scene!spatula-city.org/~im14u2c/intv!spatula-city.org/~im14u2c/intv/4-tris!sdk-1600.spatula-city.org!spatula-city.org/~im14u2c/intv/contest-2007!Homebrew programming contest:!15!Example Intellivision code!Source code for Space Patrol! ;; ------------------------------------------------------------ ;;! ;; Draw the crater strip in selected color scheme. ;;! ;; ------------------------------------------------------------ ;;! MVI COURSE, R1 ; \! ANDI #7, R1! SLR R1, 1 ; |_ Adjust color for course! ADDI #CRATCLR, R1 ; |! ADD@ R1, R0 ; /! MOVR R0, R2 ;! ADDI #7*8, R2 ; City/crater ending card #! CALL RSGGB ; Reset good guy bullets.! CALL FILLZERO.lp ; \! DECLE 25 ; |- nuke any remaining bad guys! DECLE BGMPTBL ; /! CALL FILLZERO.lp ; \! DECLE 10 ; |- and their sprites! DECLE SPAT ; /!From spatula-city.org/~im14u2c/intv/spteaser!16!Atari Homebrew Scene !Ian Bogost (LCC)!From www.bogost.com and www.quernhorst.de/atari/rf.html!17!ColecoVision (1982)!• ≈3.6
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