Difference between revisions of "Sega G80"

From Sega Retro
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==Technical Specifications==
 
==Technical Specifications==
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* Main CPU: Modified [[Z80]] running at 3.86712MHz
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* Board composition: One board
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* Sound: some combination of the following (depending on the game)
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* Main [[Central processing unit|CPU]]:{{ref|http://www.cityofberwyn.com/simulation/gameHardware/G80ref1.20.txt}}
−
** Pure discrete sound
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** [[Raster graphics|Raster]]: Zilog Z80 @ 8&nbsp;MHz (8-bit & 16-bit instructions @ 1.16 MIPS<ref name=retro/>)
−
** Speech board, with Intel 8035 + GI SP0250 speech synthesis chip
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** [[Vector graphics|Vector]]: [[Zilog Z80]] @ 3.86712&nbsp;MHz (8-bit & 16-bit instructions @ 0.561 MIPS<ref name=retro/>)
−
** USB board, with Intel 8035 and hacked up tone generation with timers and dacs for volume.
+
* [[Sound card|Sound boards]]:
−
* Video resolution: 256 x 224 (raster version)
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** Sega USB (Universal Sound Board){{ref|https://github.com/mamedev/mame/tree/master/src/mame/drivers/segag80r.c}}
−
* Board composition: one board
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*** [[Microcontroller|MCU]]: [[Intel MCS-48|Intel i8035]]{{ref|http://www.system16.com}} @ 3.12&nbsp;MHz{{ref|http://www.system16.com}} (8-bit instructions @ 3.12 MIPS, 1 [[instructions per cycle|instruction per cycle]]){{ref|http://archive.org/stream/bitsavers_inteldataSngleComponent8BitMicrocomputerDataSheet1_846962/8048_8035_HMOS_Single_Component_8-Bit_Microcomputer_DataSheet_1980}}
 +
*** [[Sound chip]]: Sega Melody Generator{{ref|https://github.com/mamedev/mame/tree/master/src/mame/audio/segag80r.c}} ([[programmable sound generator]])
 +
** Speech Board{{ref|http://www.cityofberwyn.com/simulation/gameHardware/G80ref1.20.txt}} (optional){{ref|http://www.system16.com}}
 +
*** MCU: [[Intel MCS-48|Intel i8035/i8039]]{{ref|http://www.cityofberwyn.com/simulation/gameHardware/G80ref1.20.txt}} @ 3.12&nbsp;MHz{{ref|http://www.system16.com}} (8-bit instructions @ 3.12 MIPS){{ref|http://archive.org/stream/bitsavers_inteldataSngleComponent8BitMicrocomputerDataSheet1_846962/8048_8035_HMOS_Single_Component_8-Bit_Microcomputer_DataSheet_1980}}
 +
*** [[Speech synthesis|Speech synthesizer]]: [[General Instrument SP0256|General Instrument SP0250]] ([[linear predictive coding]])
 +
** [[Sega System 1]] sound board (optional, used for ''Sindbad Mystery'' in 1983){{ref|https://github.com/mamedev/mame/tree/master/src/mame/drivers/segag80r.c}}
 +
*** Sound chips: [[Texas Instruments SN76496|Sega SN76496]] @ 4&nbsp;MHz, Sega SN76496 @ 2&nbsp;MHz
 +
* [[Raster graphics|Raster]] [[Graphics card|graphics board]]: Sega Video I{{ref|https://github.com/mamedev/mame/tree/master/src/mame/drivers/segag80r.c}}
 +
** Raster [[Video display controller|display controller]]: Sega Raster Display Controller{{ref|http://www.cityofberwyn.com/simulation/gameHardware/G80ref1.20.txt}} @ 15.468&nbsp;MHz{{ref|https://github.com/mamedev/mame/tree/master/src/mame/drivers/segag80r.c}}
 +
** [[Display resolution]]: 256×224{{ref|http://www.system16.com/hardware.php?id=687}} to 328×262 (horizontal),{{ref|https://github.com/mamedev/mame/tree/master/src/mame/drivers/segag80r.c}} 224×256 to 262×328 (vertical){{ref|http://web.archive.org/web/20130104202105/http://mamedev.org/source/src/mame/video/segag80r.c.html}}
 +
** [[List of color palettes|Color palette]] [[Colour look-up table|table]]: 256 ([[8-bit color|8-bit RGB]] [[Programmable read-only memory|PROM]]){{ref|http://www.cityofberwyn.com/simulation/gameHardware/G80ref1.20.txt}}
 +
** [[Color depth|Colors on screen]]: 64 to 128 ([[Video memory|palette RAM]]){{ref|http://www.cityofberwyn.com/simulation/gameHardware/G80ref1.20.txt}}{{ref|https://github.com/mamedev/mame/tree/master/src/mame/drivers/segag80r.c}}
 +
** [[Tile engine|Tilemap]] planes: 2 layers, horizontal and vertical [[scrolling]],{{ref|http://web.archive.org/web/20130104202105/http://mamedev.org/source/src/mame/video/segag80r.c.html}} 8×8 tiles, 4 colors per tile{{ref|http://www.cityofberwyn.com/simulation/gameHardware/G80ref1.20.txt}}{{ref|https://github.com/mamedev/mame/tree/master/src/mame/drivers/segag80r.c}}
 +
** [[Sprite (computer graphics)|Sprite]] capabilities: 28 to 32 sprites per [[Scan line|scanline]], 224 to 256 [[Texel (graphics)|sprite pixels/texels]] per scanline, 4 colors per sprite, 8×8{{ref|http://www.cityofberwyn.com/simulation/gameHardware/G80ref1.20.txt}} to 16×16{{ref|http://www.system16.com/hardware.php?id=687}} sizes
 +
* [[Vector monitor|Vector display]] controller: Sega Display Controller{{ref|http://www.cityofberwyn.com/simulation/gameHardware/G80ref1.20.txt}}
 +
** [[Color depth]]: 64 ([[List of monochrome and RGB palettes#6-bit RGB|6-bit RGB]]){{ref|https://web.archive.org/web/20130104202114/http://mamedev.org/source/src/mame/video/segag80v.c.html}}
  
 
==List of Games==
 
==List of Games==

Revision as of 08:48, 19 February 2015

Notavailable.svg
Sega G80
Manufacturer: Sega
Release Date RRP Code

The Sega G80 is an arcade system produced by Sega in 1981. It can be considered a successor to the Sega VIC Dual system, and was Sega's arcade platform of choice before the release of the Sega System 1.

The G80 was designed to be a more versatile system than those seen in arcade cabinets of the past. Rather than rely on bespoke cabinet designs for each game, Sega opted for a more cost-effective "Convert-a-Game" system (as it was marketed in the US), in which games housed on CPU boards could be easily swapped by arcade operators. It also marks Sega's recognition of the likes of Atari's Asteriods and Lunar Lander, as two variants of the G80 system exist - one which displays raster graphics, and another that displays vector graphics.

The G80 gets its name from its CPU - a modified Z80 processor (which is attached to each game). The G80 is largely identical to the Z80, however the "ld (address),a" instruction (opcode 32h) was modified to mangle the address written to — an early form of copy protection. The mangling system is rather complicated, and differs from game to game.

The raster version of the Sega G80 board is not fondly remembered in the history of video games, however the platform did provide a basis for many reasonably successful vector-based games from the company, some of which, such as Space Fury, Tac/Scan and perhaps most famously, Star Trek: Strategic Operations Simulator, saw home console/computer ports.

Technical Specifications

List of Games

Raster

Vector


Sega arcade boards
Originating in arcades








  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 http://www.cityofberwyn.com/simulation/gameHardware/G80ref1.20.txt
  2. ↑ 2.0 2.1 Cite error: Invalid <ref> tag; no text was provided for refs named retro
  3. ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 https://github.com/mamedev/mame/tree/master/src/mame/drivers/segag80r.c
  4. ↑ 4.0 4.1 4.2 4.3 http://www.system16.com
  5. ↑ 5.0 5.1 http://archive.org/stream/bitsavers_inteldataSngleComponent8BitMicrocomputerDataSheet1_846962/8048_8035_HMOS_Single_Component_8-Bit_Microcomputer_DataSheet_1980
  6. ↑ https://github.com/mamedev/mame/tree/master/src/mame/audio/segag80r.c
  7. ↑ 7.0 7.1 [ ]
  8. ↑ 8.0 8.1 http://mamedev.org/source/src/mame/video/segag80r.c.html (Wayback Machine: 2013-01-04 20:21)
  9. ↑ http://mamedev.org/source/src/mame/video/segag80v.c.html (Wayback Machine: 2013-01-04 20:21)


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