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Sega System 1

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System1 PCB1.jpg
Fast facts on Sega System 1
Manufacturer: Sega
Release Date RRP Code
Arcade
JP (prototype)
1982-12 ¥?  ?
Arcade
World
1983-07  ?


The Sega System 1 is an arcade platform officially debuted by Sega in 1983,[1] based on earlier 1982 prototype hardware. It is a Z80-based platform and the first in the decade-long "System" series of arcade boards.

The System 1 was a relatively popular arcade board for its day, supported not only by Sega, but by Japanese developers Coreland and VIC Tokai between 1983 and 1987. In 1985 it was succeeded by the slightly more powerful Sega System 2 board, though new games were released for both systems concurrently. Many of the System 1's games were ported to the SG-1000 and Sega Master System consoles.

Technical specifications

System 1

  • Board composition: One board
    • Master clock rate: 19.99982 MHz[2]
  • Main CPU: Zilog Z80 @ 4 MHz (8/16-bit instructions, 0.58 MIPS)
  • Sound CPU: Zilog Z80 @ 4 MHz (8/16-bit instructions, 0.58 MIPS)
  • Sound chips: Sega SN76496 @ 4 MHz, Sega SN76496 @ 2 MHz
  • MCU: Intel 8751[2]

Graphics

  • Graphics chipset:[2]
  • Video resolution: 256×224 (active), 640×260 (overscan)[2]
    • Scanlines: 260 (224 active, 36 VBlank)
    • Pixel clock rate: 9.99991 MHz (3.446099 MHz active, 6.55381 MHz HBlank/VBlank)
    • Refresh rate: 60.0952 Hz (VSync)
  • Color palette: 4096[6]
    • Colors on screen: 2048[2]
  • Sprite plane: Line buffer, double buffering, 16 colors per sprite, sprite flipping, hardware collision detection[6][2]
    • Sprites on screen: 128 sprites (2 KB sprite attributes, 16 bytes per sprite)[5]
    • Sprite sizes: 8×8 to 256×224 texels
    • Line buffer fillrate: 9.99991 MPixels/s
    • Sprites per scanline: 32 sprites, 640 texels
  • Background planes: 2 tilemap layers (1 static, 1 scrolling), 8×8 tiles[6][2]
    • Tilemap sizes: 256×256 for both planes

Memory

  • Memory: 155.75 KB (52 KB main, 93.75 KB video, 10 KB sound)
  • RAM: 19.5 KB[2]
  • ROM: 136.25 KB
    • Main: 48 KB
    • Video: 80.25 KB (48 KB tiles, 32 KB sprites, 256 bytes palette)
    • Sound: 8 KB

Prototype

Super Locomotive in 1982 ran on prototype arcade hardware that was very similar to the Sega System 1 later released in 1983. Super Locomotive had largely identical specifications, but with the following differences:[8][9][10]

Graphics

  • Graphics chipset:
    • Sega 315-5011 sprite line comparator: 16‑bit line buffer RAM (11.79648 MHz, 23.59296 MB/s), 7.86432 MHz sprite line buffer render clock, 3.93216 MHz sprite line buffer scan/erase/pixel clock[5]
  • Video resolution: 248×224 (active), 256×256 (overscan)
    • Pixel clock rate: 3.93216 MHz
    • Refresh rate: 60 Hz
  • Color palette: 1568
    • Colors on screen: 768
  • Sprite plane:
    • Sprites on screen: 32 sprites (512 bytes sprite attributes, 16 bytes per sprite), 64 sprites with raster interrupt
    • Sprite sizes: 8×8 to 248×224 texels
    • Line buffer fillrate: 7.86432 MPixels/s
    • Sprites per scanline: 32 sprites, 512 texels

Memory

  • Memory: 113.3125 KB (50 KB main, 53.3125 KB video, 10 KB sound)
  • RAM: 7.78125 KB
    • Main: 2 KB
    • Video: 3.78125 KB SRAM (1.75 KB video, 512 bytes sprite atttributes, 1.5 KB sprite line buffers, 32 bytes scrolling)
    • Sound: 2 KB
  • ROM: 105.53125 KB
    • Main: 48 KB
    • Video: 49.53125 KB (48 KB graphics, 1.53125 KB palette)
    • Sound: 8 KB

Photo gallery

List of games

References

Sega Arcade Boards
Originating in Arcades
76 77 78 79 80 81 82 83 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
Fonz Galaxian Zaxxon Appoooh X Board Model 2 Hikaru Atomiswave
Blockade G80 Hang-On / Space Harrier Model 1 H1 Model 3 NAOMI 2
VIC Dual System 1 System 24 NAOMI
VCO Object LaserDisc System SP
System 2 System 18
System 16
OutRun System 32
Gigas
Y Board
Based on Consumer Hardware
83 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 15
SG-1000 System E System C Triforce Europa-R RingEdge 2
Mega-Tech System Sega Titan Video Chihiro Nu
Mega Play Lindbergh
RingEdge
RingWide
Hardware Series / Generations
1960s 1970s 1980s 1990s 2000s 2010s
Electro-mechanical systems Sega System series Sega NAOMI series
Discrete logic systems Super Scaler series Post-NAOMI systems
Pre-System boards Sega Model series