Codex Gamicus
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The FM Towns (エフエムタウンズ Efu Emu Taunzu?) system is a Japanese personal computer, built by Fujitsu from February 1989 to the summer of 1997.

Graphics[]

The FM Towns featured video modes ranging from 320×200 to 720×512 resolutions,[1] with 16 to 32,768 simultaneous colours out of a possible 4096 to 16.777 million (depending on the video mode); most of these video modes had two memory pages, and it allowed the use of up to 1024 sprites of 16×16 pixels each. It also had a built-in font ROM for the display of kanji characters.

One unique feature of the FM Towns system was the ability to overlay different video modes; for example, the 320×200 video mode with 32,768 colours could be overlaid with a 640×480 mode using 16 colours, which allowed games to combine high-colour graphics with high-resolution kanji text.

It uses 640 KB of video RAM, including 512 KB VRAM and 128 KB sprite RAM.[2] FM Towns supports the following graphics modes:

Bitmap modes:[3]

  1. 640×819 virtual (640×400 display) @ 16 out of 4096 colors - overlay support with mode 2
  2. 640×819 virtual (640×200 display) @ 16 out of 4096 colors - overlay support with mode 1
  3. 1024×512 virtual (640×480 display) @ 16 out of 4096 colors - overlay support with modes 5 or 10
  4. 1024×512 virtual (640×400 display) @ 16 out of 4096 colors - overlay support with mode 6
  5. 256×512 virtual (256×256 display, interlaced) @ 32,768 colors - overlay support with modes 3 or 10
  6. 256×512 virtual (256×256 display, progressive) @ 32,768 colors - overlay support with mode 4
  7. 256×512 virtual (256×240 display, interlaced) @ 32,768 colors - overlay support with mode 9
  8. 256×512 virtual (256×240 display, progressive) @ 32,768 colors - overlay support with mode 11
  9. 512×256 virtual (360×240 display) @ 32,768 colors - overlay support with mode 7
  10. 512×256 virtual (320×240 display, 31 kHz) @ 32,768 colors - overlay support with modes 3 or 5
  11. 512×256 virtual (320×240 display, 15 kHz) @ 32,768 colors - overlay support with mode 8
  12. 1024×512 virtual (640×480 display) @ 256 out of 16,777,216 colors - overlay not supported
  13. 1024×512 virtual (640×400 display) @ 256 out of 16,777,216 colors - overlay not supported
  14. 1024×512 virtual (720×480 display) @ 256 out of 16,777,216 colors - overlay not supported
  15. 512×512 virtual (320×480 display, progressive) @ 32,768 colors - overlay not supported
  16. 512×512 virtual (320×480 display, interlaced) @ 32,768 colors - overlay not supported
  17. 512×512 virtual (512×480 display, progressive) @ 32,768 colors - overlay not supported
  18. 512×512 virtual (512×480 display, interlaced) @ 32,768 colors - overlay not supported

Sprite layer:[3]

  • Resolution: 256×240 pixels[3]
  • Colors: 256 on screen out of 32,768 palette[4]
  • Sprite RAM: 128 KB (8 KB attributes, 120 KB pattern/colour data)[1]
  • Maximum sprite count: Up to 1024 on screen[5]
  • Sprite size: 16×16 pixels[5]
  • Colors per sprite: 16[1]
  • Overlay support: Bitmap modes 1-11[3]

Up to two graphical layers can be overlaid, whether it is two bitmap layers, or the sprite layer with a bitmap background layer. The latter is useful for action games, though the sprite function is not as advanced as that of rival 16-bit computer, the Sharp X68000.[3] When the sprite layer is used, it is rendered to VRAM layer 1 on top, with the bitmap background as VRAM layer 0 below. When two bitmap layers are used, then both are rendered to VRAM layers 0 and 1.[1]

See also[]

  • List of FM Towns games
  • FM-7
  • FM Towns Marty

References[]