Sega System 1

From Sega Retro

System1 PCB1.jpg
Sega System 1
Manufacturer: Sega
Release Date RRP Code

The Sega System 1 is an arcade platform introduced 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.

Specifications

System 1

  • Board composition: One board
    • Master clock rate: 19.99982 MHz
  • 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
  • Graphics chipset:[2]
    • Sega 315-5011 sprite line comparator
    • Sega 315-5012 sprite generator
    • Sega 315-5049 tilemap chip
  • MCU: Intel 8751[2]
  • RAM: 82 KB[2]
    • Main: 4 KB
    • Video: 12 KB (4 KB video, 2 KB sprites, 2 KB palette, 4 KB collision)
    • Sound: 2 KB
    • MCU: 64 KB
  • 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[3]
    • Colors on screen: 2048[2]
  • Sprite plane: Line buffer, double buffering, 32 sprites on screen, 16 colors per sprite, sprite flipping, hardware collision detection[3][2]
    • Sprite sizes: 8×8 to 256×224 texels
    • Texels per scanline: 384 (active scanlines) to 640 (VBlank scanlines)
    • Sprites per scanline: 32
    • Line buffer fillrate: 6.55381 MPixels/s
  • Background planes: 2 tilemap layers (1 static, 1 scrolling), 8×8 tiles[3][2]
    • Tilemap sizes: 256×256 for both planes

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 the following differences:[4][5][6]

  • Graphics chipset:
    • Sega 315-5011 sprite line comparator
    • Sega 315-5012 sprite generator
  • Display resolution: 248×224
    • Overscan resolution: 256×256
  • Refresh rate: 60 Hz
    • Frame rate: 60 FPS
  • Color palette: 1568
    • Colors on screen: 768
  • Sprite plane:

Gallery

List of Games

References


Sega arcade boards
Originating in arcades









Console-based hardware








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PC-based hardware








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