Difference between revisions of "Sega G80"

Revision as of 04:22, 12 September 2023

Sega G80

Manufacturer: Sega

Release	Date	RRP	Code
JP	1981	¥?	?
US	1981-06^[1]	$?	?
DE	198x	?	?

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 Sega G80 platform provided 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.

Hardware

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. Announced at Visions '81^[2], Sega's plan was to be able to cut install times down to 15 minutes, while also minimising production costs and tackling the poor resale value of used games^[2]. As a result, "ConvertaPaks" would cost less to buy than brand new cabinets^[3] (about $1,000 USD each^[1], versus the $3,000 Sega estimated the average arcade game to cost in 1981^[4]).

The G80 system consists of a card cage with a 6 slot backplane that can be populated in different game configurations from a selection of 10+ different pluggable boards, allowing it to be configured as either a raster system if a raster video board is inserted, or a vector system that can display color vector graphics (or X/Y "Colorbeam" games, as Sega called them at the time).

The G80 gets its name from its Z80 CPU which was coupled with a custom security chip to prevent operators from abusing the swappable system. The security chip would obfuscate the "ld (address),a" instruction (opcode 32h) differently based on the security chip installed — an early form of copy protection. The mangling algorithms are rather complicated, and differ from security chip to security chip.^[5]

History

Space Odyssey was the first game to use the G80 system, followed by Space Fury^[2].

For a while, Sega believed the "Convert-a-Game" concept was the future. David Rosen predicted that improvements in microprocessor technology would mean players would be constantly seeking new experiences, and as a result, arcade operators would have to keep changing their lineup of games; a business strategy that would not be economically viable if entirely new systems had to be purchased from manufacturers (who in turn relied on these new sales to stay in business)^[6].

At the time, Sega sold their products to a network of distributors in the US, who would then sell on to customers. By only selling boards rather than fully assembled cabinets, it was possible for Sega to bypass its distributors after the initial cabinet was sold. It was also noted that a fixed hardware specification could mean games designed for it would appear outdated within months, and thus be harder to sell.

Despite assurances from Sega that its current sales model would not change, and that the G80 board could be upgraded, it struggled to convince its distributors were, and so, despite advocating its benefits across 1981 and 1982, was forced to continue to release games like Pengo and Zaxxon on bespoke hardware. Sega's last G80 game would release in 1983.

In hindsight, Sega's analysis was correct, but its solution came to the market too early. Genuine arcade standards would arrive in the years which followed; the JAMMA specifications from 1985/1986 are built around the same idea of swappable arcade PCBs, but do not tie developers down to specific hardware (it is mainly the input and output connectors that are standardised instead, meaning the large cabinets could stay in place). The idea of "swappable games" never went away; ten years later, the reuse of hardware would become necessary for arcade companies to survive, particularly when home consoles became the dominant form of playing video games.

Sega was not the first company to try and produce a reusable arcade system. In 1980, Data East released the DECO Cassette System which would load games from compact cassette, however this system was prone to failure due to the mechanical nature of the system (and the potential for tapes to be demagentised).

Technical specifications

Board composition: One board
Main CPU:^[7]

Raster: Zilog Z80 @ 8 MHz (8/16-bit instructions, 1.16 MIPS)
Vector: Zilog Z80 @ 3.86712 MHz (8/16-bit instructions, 0.561 MIPS)

Sound boards:^[7]^[5]

Sega USB (Universal Sound Board)^[8]

MCU: Intel i8035 @ 3.12 MHz (8-bit instructions, 3.12 MIPS, 1 instruction per cycle)
Sound chip: Sega Melody Generator (programmable sound generator)

Speech Board (optional)

MCU: Intel i8035/i8039 @ 3.12 MHz (8-bit instructions, 3.12 MIPS)
Speech synthesizer: General Instrument SP0250 (linear predictive coding)

Sega System 1 sound board (optional, used for Sindbad Mystery in 1983)

Sound chips: Sega SN76496 @ 4 MHz, Sega SN76496 @ 2 MHz

Raster graphics board: Sega Video I^[5]

Raster display controller: Sega Raster Display Controller @ 15.468 MHz
Video resolution:

Horizontal: 256×224 (display), 328×262 (overscan)
Vertical: 224×256 (display), 262×328 (overscan)^[9]

Color palette table: 256 (8-bit RGB PROM)
Colors on screen: 64 to 128 (palette RAM)
Tilemap planes: 2 layers, horizontal and vertical scrolling,^[9] 8×8 tiles, 4 colors per tile
Sprite capabilities: 28 to 32 sprites per scanline, 224 to 256 sprite pixels/texels per scanline, 4 colors per sprite, 8×8 to 16×16 sizes^[7]

Vector display controller: Sega Display Controller^[10]

Color depth: 64 (6-bit RGB)^[11]

RAM:^[7]^[5]

Raster: 14 KB (2 KB main, 8 KB video, 4 KB audio)
Vector: 10 KB (2 KB main, 4 KB video, 4 KB audio)
Monster Bash & Sindbad Mystery: 24 KB (4 KB main, 16 KB video, 4 KB audio)

List of games

Raster

005 (1981)
Astro Blaster (1981)
Space Odyssey (1981)
Monster Bash (1982)
Pig Newton (1983)
Sindbad Mystery (1983)

Vector

Space Fury (1981)
Eliminator (1981)
Battle Star (1982)
Star Trek: Strategic Operations Simulator (1982)
Tac/Scan (1982)
Zektor (1982)

Promotional material

US flyer
US "New Games" flyer

References

Sega arcade boards
Originating in arcades
77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 VIC Dual G80 Zaxxon VCO Object System 1 LaserDisc Appoooh Hang-On System 2 System 16 OutRun Gigas X Board Y Board System 24 System 18 System 32 Model 1 Model 2 H1 Board Model 3
Console-based hardware
84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 SG-1000 System E System C Mega-Tech System Mega Play Sega Titan Video NAOMI Hikaru NAOMI 2 Atomiswave System SP Chihiro Triforce
PC-based hardware
05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Lindbergh Europa-R RingEdge RingWide RingEdge 2 Nu Nu 1.1 Nu 2 ALLS

[:File:ConvertaGames_Arcade_US_Flyer.pdf_p2-1] 1.0 ^1.1 File:ConvertaGames Arcade US Flyer.pdf, page 2

[:File:CashBox_US_1981-07-04_2.pdf_p57-2] 2.0 ^2.1 ^2.2 Cash Box, "July 4, 1981 (Part 2 of 2)" (US; 1981-07-04), page 57

[:File:CashBox_US_1981-07-04_2.pdf_p58-3] Cash Box, "July 4, 1981 (Part 2 of 2)" (US; 1981-07-04), page 58

[:File:ConvertaGame_Arcade_US_Flyer.pdf_p2-4] File:ConvertaGame Arcade US Flyer.pdf, page 2

[.5Bhttps:.2F.2Fgithub.com.2Fmamedev.2Fmame.2Ftree.2Fmaster.2Fsrc.2Fmame.2Fdrivers.2Fsegag80r.cpp_Sega_G-80_raster_hardware_.28MAME.29.5D-5] 5.0 ^5.1 ^5.2 ^5.3 Sega G-80 raster hardware (MAME)

[:File:CashBox_US_1981-12-26.pdf_p84-6] Cash Box, "December 26, 1981" (US; 1981-12-26), page 84

[Sega_G80_Hardware_Reference_.281997-10-25.29-7] 7.0 ^7.1 ^7.2 ^7.3 Sega G80 Hardware Reference (1997-10-25)

[:File:DataBus_US_0401.pdf_p2-8] Data Bus, "March 1983: Volume 4, Number 1" (US; 1983-03-xx), page 2

[.5Bhttps:.2F.2Fgithub.com.2Fmamedev.2Fmame.2Ftree.2Fmaster.2Fsrc.2Fmame.2Fvideo.2Fsegag80r.cpp_Sega_G-80_raster_video_hardware_.28MAME.29.5D-9] 9.0 ^9.1 Sega G-80 raster video hardware (MAME)

[.5Bhttps:.2F.2Fgithub.com.2Fmamedev.2Fmame.2Ftree.2Fmaster.2Fsrc.2Fmame.2Fdrivers.2Fsegag80v.cpp_Sega_G-80_vector_hardware_.28MAME.29.5D-10] Sega G-80 vector hardware (MAME)

[.5Bhttps:.2F.2Fgithub.com.2Fmamedev.2Fmame.2Ftree.2Fmaster.2Fsrc.2Fmame.2Fvideo.2Fsegag80v.cpp_Sega_G-80_vector_video_hardware_.28MAME.29.5D-11] Sega G-80 vector video hardware (MAME)

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@@ Line 1: / Line 1: @@
 {{ConsoleBob
 | logos=
-| consoleimage=
+| consoleimage=G80 Arcade.jpg
-| imgwidth=
 | name=
 | maker=[[Sega]]
-| releases={{releases
+| processor=[[Zilog Z80]]
-| arcade_date_world=1981-03
+| releases={{releasesArcade
+| g80_date_us=1981-06{{fileref|ConvertaGames Arcade US Flyer.pdf|page=2}}
+| g80_date_jp=1981
+| g80_date_de=198x
 }}
 }}
 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 ''[[Asteroids]]'' and ''Lunar Lander'', as two variants of the G80 system exist - one which displays raster graphics, and another that displays color vector graphics.
+The Sega G80 platform provided 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.
+==Hardware==
+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. Announced at [[Visions '81]]{{magref|cb|1981-07-042|57}}, Sega's plan was to be able to cut install times down to 15 minutes, while also minimising production costs and tackling the poor resale value of used games{{magref|cb|1981-07-042|57}}. As a result, "ConvertaPaks" would cost less to buy than brand new cabinets{{magref|cb|1981-07-042|58}} (about $1,000 USD each{{fileref|ConvertaGames Arcade US Flyer.pdf|page=2}}, versus the $3,000 Sega estimated the average arcade game to cost in 1981{{fileref|ConvertaGame Arcade US Flyer.pdf|page=2}}).
+The G80 system consists of a card cage with a 6 slot backplane that can be populated in different game configurations from a selection of 10+ different pluggable boards, allowing it to be configured as either a raster system if a raster video board is inserted, or a vector system that can display color vector graphics (or X/Y "Colorbeam" games, as Sega called them at the time).
+The G80 gets its name from its Z80 CPU which was coupled with a custom security chip to prevent operators from abusing the swappable system.  The security chip would obfuscate the "ld (address),a" instruction (opcode 32h) differently based on the security chip installed — an early form of copy protection. The mangling algorithms are rather complicated, and differ from security chip to security chip.{{ref|[https://github.com/mamedev/mame/tree/master/src/mame/drivers/segag80r.cpp Sega G-80 raster hardware (MAME)]}}
-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 [https://github.com/mamedev/mame/blob/master/src/mame/machine/segag80.c rather complicated, and differs from game to game].
+==History==
+''[[Space Odyssey]]'' was the first game to use the G80 system, followed by ''[[Space Fury]]''{{magref|cb|1981-07-042|57}}.
-The Sega G80 platform provided 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.
+For a while, Sega believed the "Convert-a-Game" concept was the future. [[David Rosen]] predicted that improvements in microprocessor technology would mean players would be constantly seeking new experiences, and as a result, arcade operators would have to keep changing their lineup of games; a business strategy that would not be economically viable if entirely new systems had to be purchased from manufacturers (who in turn relied on these new sales to stay in business){{magref|cb|1981-12-26|84}}.
+At the time, Sega sold their products to a network of distributors in the US, who would then sell on to customers. By only selling boards rather than fully assembled cabinets, it was possible for Sega to bypass its distributors after the initial cabinet was sold. It was also noted that a fixed hardware specification could mean games designed for it would appear outdated within months, and thus be harder to sell.
+Despite assurances from Sega that its current sales model would not change, and that the G80 board could be upgraded, it struggled to convince its distributors were, and so, despite advocating its benefits across 1981 and 1982, was forced to continue to release games like ''[[Pengo]]'' and ''[[Zaxxon]]'' on bespoke hardware. Sega's last G80 game would release in 1983.
+In hindsight, Sega's analysis was correct, but its solution came to the market too early. Genuine arcade standards would arrive in the years which followed; the JAMMA specifications from 1985/1986 are built around the same idea of swappable arcade PCBs, but do not tie developers down to specific hardware (it is mainly the input and output connectors that are standardised instead, meaning the large cabinets could stay in place). The idea of "swappable games" never went away; ten years later, the reuse of hardware would become necessary for arcade companies to survive, particularly when home consoles became the dominant form of playing video games.
+Sega was not the first company to try and produce a reusable arcade system. In 1980, [[Data East]] released the [[wikipedia:DECO Cassette System|DECO Cassette System]] which would load games from compact cassette, however this system was prone to failure due to the mechanical nature of the system (and the potential for tapes to be demagentised).
-==Technical Specifications==
+==Technical specifications==
 {{multicol|
 * Board composition: One board
-* Main [[wikipedia:Central processing unit|CPU]]:
+* Main [[wikipedia:Central processing unit|CPU]]:{{intref|Sega G80 Hardware Reference (1997-10-25)}}
-** [[wikipedia:Raster graphics|Raster]]: Zilog Z80 @ 8&nbsp;MHz (8-bit & 16-bit instructions @ 1.16 [[wikipedia:Instructions per second|MIPS]])
+:* [[wikipedia:Raster graphics|Raster]]: [[Zilog]] [[Z80]] @ 8&nbsp;MHz (8/16-bit instructions, 1.16 [[wikipedia:Instructions per second|MIPS]])
-** [[wikipedia:Vector graphics|Vector]]: [[Zilog Z80]] @ 3.86712&nbsp;MHz (8-bit & 16-bit instructions @ 0.561 MIPS)
+:* [[wikipedia:Vector graphics|Vector]]: [[Zilog Z80]] @ 3.86712&nbsp;MHz (8/16-bit instructions, 0.561 MIPS)
-* [[wikipedia:Sound card|Sound boards]]:
+* [[wikipedia:Sound card|Sound boards]]:{{intref|Sega G80 Hardware Reference (1997-10-25)}}{{ref|[https://github.com/mamedev/mame/tree/master/src/mame/drivers/segag80r.cpp Sega G-80 raster hardware (MAME)]}}
-** Sega USB (Universal Sound Board)
+:* Sega USB (Universal Sound Board){{magref|databus|0401|2}}
-*** [[wikipedia:Microcontroller|MCU]]: [[wikipedia:Intel MCS-48|Intel i8035]] @ 3.12&nbsp;MHz (8-bit instructions @ 3.12 MIPS, 1 [[wikipedia:Instructions per cycle|instruction per cycle]])
+::* [[wikipedia:Microcontroller|MCU]]: [[Intel]] [[i8035]] @ 3.12&nbsp;MHz (8-bit instructions, 3.12 MIPS, 1 [[wikipedia:Instructions per cycle|instruction per cycle]])
-*** [[wikipedia:Sound chip|Sound chip]]: Sega Melody Generator ([[wikipedia:Programmable sound generator|programmable sound generator]])
+::* [[wikipedia:Sound chip|Sound chip]]: Sega Melody Generator ([[wikipedia:Programmable sound generator|programmable sound generator]])
-** Speech Board (optional)
+:* Speech Board (optional)
-*** MCU: [[wikipedia:Intel MCS-48|Intel i8035/i8039]] @ 3.12&nbsp;MHz (8-bit instructions @ 3.12 MIPS)
+::* MCU: [[Intel]] [[i8035]]/[[i8039]] @ 3.12&nbsp;MHz (8-bit instructions, 3.12 MIPS)
-*** [[wikipedia:Speech synthesis|Speech synthesizer]]: [[wikipedia:General Instrument SP0256|General Instrument SP0250]] ([[wikipedia:Linear predictive coding|linear predictive coding]])
+::* [[wikipedia:Speech synthesis|Speech synthesizer]]: [[wikipedia:General Instrument SP0256|General Instrument SP0250]] ([[wikipedia:Linear predictive coding|linear predictive coding]])
-** [[Sega System 1]] sound board (optional, used for ''Sindbad Mystery'' in 1983)
+:* [[Sega System 1]] sound board (optional, used for ''Sindbad Mystery'' in 1983)
-*** Sound chips: [[wikipedia:Texas Instruments SN76496|Sega SN76496]] @ 4&nbsp;MHz, Sega SN76496 @ 2&nbsp;MHz
+::* Sound chips: Sega [[SN76496]] @ 4&nbsp;MHz, Sega SN76496 @ 2&nbsp;MHz
-* [[wikipedia:Raster graphics|Raster]] [[wikipedia:Graphics card|graphics board]]: Sega Video I
+* [[wikipedia:Raster graphics|Raster]] [[wikipedia:Graphics card|graphics board]]: Sega Video I{{ref|[https://github.com/mamedev/mame/tree/master/src/mame/drivers/segag80r.cpp Sega G-80 raster hardware (MAME)]}}
-** Raster [[wikipedia:Video display controller|display controller]]: Sega Raster Display Controller @ 15.468&nbsp;MHz
+:* Raster [[wikipedia:Video display controller|display controller]]: Sega Raster Display Controller @ 15.468&nbsp;MHz
-** Video resolution:
+:* Video resolution:
-*** Horizontal: 256×224{{ref|http://www.system16.com}} (display), 328×262{{ref|https://github.com/mamedev/mame/tree/master/src/mame/drivers/segag80r.cpp}} (overscan)
+::* Horizontal: 256×224 (display), 328×262 (overscan)
-*** Vertical: 224×256 (display), 262×328{{ref|http://web.archive.org/web/20130104202105/mamedev.org/source/src/mame/video/segag80r.c.html}} (overscan)
+::* Vertical: 224×256 (display), 262×328 (overscan){{ref|[https://github.com/mamedev/mame/tree/master/src/mame/video/segag80r.cpp Sega G-80 raster video hardware (MAME)]}}
-** [[Palette|Color palette]] [[wikipedia:Colour look-up table|table]]: 256 ([[wikipedia:8-bit color|8-bit RGB]] [[wikipedia:Programmable read-only memory|PROM]])
+:* [[Palette|Color palette]] [[wikipedia:Colour look-up table|table]]: 256 ([[wikipedia:8-bit color|8-bit RGB]] [[wikipedia:Programmable read-only memory|PROM]])
-** [[wikipedia:Color depth|Colors on screen]]: 64 to 128 ([[wikipedia:Video memory|palette RAM]])
+:* [[wikipedia:Color depth|Colors on screen]]: 64 to 128 ([[wikipedia:Video memory|palette RAM]])
-** [[wikipedia:Tile engine|Tilemap]] planes: 2 layers, horizontal and vertical [[wikipedia:Scrolling|scrolling]], 8×8 tiles, 4 colors per tile
+:* [[wikipedia:Tile engine|Tilemap]] planes: 2 layers, horizontal and vertical [[wikipedia:Scrolling|scrolling]],{{ref|[https://github.com/mamedev/mame/tree/master/src/mame/video/segag80r.cpp Sega G-80 raster video hardware (MAME)]}} 8×8 tiles, 4 colors per tile
-** [[Sprite]] capabilities: 28 to 32 sprites per [[wikipedia:Scan line|scanline]], 224 to 256 [[wikipedia:Texel (graphics)|sprite pixels/texels]] per scanline, 4 colors per sprite, 8×8 to 16×16 sizes
+:* [[Sprite]] capabilities: 28 to 32 sprites per [[wikipedia:Scan line|scanline]], 224 to 256 [[wikipedia:Texel (graphics)|sprite pixels/texels]] per scanline, 4 colors per sprite, 8×8 to 16×16 sizes{{intref|Sega G80 Hardware Reference (1997-10-25)}}
-* [[wikipedia:Vector monitor|Vector display]] controller: Sega Display Controller
+* [[wikipedia:Vector monitor|Vector display]] controller: Sega Display Controller{{ref|[https://github.com/mamedev/mame/tree/master/src/mame/drivers/segag80v.cpp Sega G-80 vector hardware (MAME)]}}
-** [[wikipedia:Color depth|Color depth]]: 64 ([[wikipedia:List of monochrome and RGB palettes#6-bit RGB|6-bit RGB]])
+:* [[wikipedia:Color depth|Color depth]]: 64 ([[wikipedia:List of monochrome and RGB palettes#6-bit RGB|6-bit RGB]]){{ref|[https://github.com/mamedev/mame/tree/master/src/mame/video/segag80v.cpp Sega G-80 vector video hardware (MAME)]}}
-* [[RAM]]:{{ref|https://github.com/mamedev/mame/blob/master/src/mame/drivers/segag80r.cpp}}
+* [[RAM]]:{{intref|Sega G80 Hardware Reference (1997-10-25)}}{{ref|[https://github.com/mamedev/mame/tree/master/src/mame/drivers/segag80r.cpp Sega G-80 raster hardware (MAME)]}}
-** Default: 10 KB (2 KB main, 8 KB [[VRAM|video]])
+:* Raster: 14&nbsp;[[Byte|KB]] (2&nbsp;KB main, 8&nbsp;KB [[VRAM|video]], 4 KB audio)
-** ''Monster Bash'': 20 KB (4 KB main, 16 KB video)
+:* Vector: 10 KB (2 KB main, 4 KB video, 4 KB audio)
-** ''Sindbad Mystery'': 22 KB (4 KB main, 16 KB video, 2 KB sound)
+:* ''Monster Bash'' & ''Sindbad Mystery'': 24&nbsp;KB (4&nbsp;KB main, 16&nbsp;KB video, 4 KB audio)
 }}
-==List of Games==
+==List of games==
 ===Raster===
 {{multicol|
@@ Line 69: / Line 87: @@
 * ''[[Zektor]]'' (1982)
 }}
+==Promotional material==
+<gallery>
+ConvertaGame Arcade US Flyer.pdf|US flyer
+ConvertaGames Arcade US Flyer.pdf|US "New Games" flyer
+</gallery>
+==References==
+<references/>
 {{Sega Arcade Boards}}
 [[Category:Pre-System 1 arcade systems]]