Turbo Duo - Technical Specifications

Technical Specifications

• CPU: 8-bit HuC6280A, a modified 65C02 running at 3.58 or 7.16 MHz (switchable by software). Features integrated bankswitching hardware (driving a 21-bit external address bus from a 6502-compatible 16-bit address bus), an integrated general-purpose I/O port, a timer, block transfer instructions, and dedicated move instructions for communicating with the HuC6270A VDC.
• GPU: A dual graphics processor setup. One 16-bit HuC6260 Video Color Encoder (VCE), and one 16-bit HuC6270A Video Display Controller (VDC). The HuC6270A featured Port-based I/O similar to the TMS99xx VDP family.
• Resolution:
  • X (Horizontal) Resolution: variable, maximum of 512 (programmable in increments of 8 pixels)
  • Y (Vertical) Resolution: variable, maximum of 240 (programmable in increments of 8 pixels)
  • The vast majority of TurboGrafx-16 games use 256×224, though some games, such as Sherlock Holmes Consulting Detective did use 512×224. Chris Covell's 'High-Resolution Slideshow' uses 512×240.
• Color:
  • Depth: 9 bit
  • Colors available: 512
  • Colors onscreen: Maximum of 481 (241 background, 240 sprite)
  • Palettes: Maximum of 32 (16 for background tiles, 16 for sprites)
  • Colors per palette: Maximum of 16
• Sprites:
  • Simultaneously displayable: 64
  • Sizes: 16×16, 16×32, 32×16, 32×32, 32×64
  • Palette: Each sprite can use up to 15 unique colors (one color must be reserved as transparent) via one of the 16 available sprite palettes.
  • Layers: The HuC6270A VDC was capable of displaying one sprite layer. Sprites could be placed either in front of or behind background tiles.
• Tiles:
  • Size: 8×8
  • Palette: Each background tile can use up to 16 unique colors via one of the 16 available background palettes. The first color entry of each background palette must be the same across all background palettes.
  • Layers: The HuC6270A VDC was capable of displaying one background layer.
• Memory:
  • Work RAM: 8KB
  • Video RAM: 64KB
  • Additional 192KB of built in Memory (System 3.0)
• Audio capacity:
  • 6 PSG audio channels, programmable through the HuC6280A CPU.
  • CD titles add Redbook CD-DA sound, and a single ADPCM channel to the existing sound capabilities of the TurboDuo.
• Game Media:
  • TurboChip (HuCARD in Japan): A thin, card-like game media. The largest Japanese HuCard games were up to 20Mbit in size.
  • Excluding the TurboExpress (TurboChip only), all TurboGrafx-16 hardware could play the entire TurboChip library, and every CD system could play all the various CD format games - with the right system card and/or HuCard adaptor.
  • Interestingly, Japanese systems cannot play US TurboChips without a required internal modification. Some modifications allow Japanese systems to play US and Japanese cards right from the HuCard port, other modifications require a HuCard converter as well.