TurboDuo

The TurboDuo is a fourth-generation video game console developed by NEC and Hudson Soft for the North American market. The TurboDuo, released in October 1992, is the North American version of the PC Engine Duo, Japanese game console released in September 1991.

In the United States, the TurboDuo was marketed by Turbo Technologies, Inc. of Los Angeles, a joint venture of NEC and Hudson Soft. It was established to market NEC consoles in North America after NEC Home Electronics USA failed to effectively market the platform satisfactorily.

The TurboDuo integrates the capabilities of the TurboGrafx-16 and its CD-ROM drive into a single, redesigned unit with an updated BIOS and 192 KB of additional RAM. The 192 KB RAM increase was previously only available by adding the Super System Card.

The RAM increase and BIOS update afford the TurboDuo and PC Engine Duo compatibility with all CD-ROM² and Super CD-ROM² titles (Japanese and North American). Like the TurboGrafx-CD, the TurboDuo can read Compact Disc Digital Audio and CD+G discs. The TurboDuo, however, cannot read PC Engine HuCards without modification or an adapter. With a HuCard adapter and a Japanese Arcade Card Duo, the TurboDuo can also read Japanese Arcade CD-ROM² games.

Marketing

Japan

When the PC Engine Duo launched in Japan on September 21, 1991, it retailed for ¥59,800. The product garnered a Good Design Award.

NEC later revised the design of the console to reduce both manufacturing costs and the sale price. This new version, the PC Engine Duo-R (PCエンジンDuo-R, Pī Shī Enjin Duo Āru), went to market on March 25, 1993 with a retail price of ¥39,800. The Duo-R omits the 3.5 mm phone connector for headphones, and the locking switch for the lid of the Duo's top-loading CD-ROM drive. The Duo-R has an off-white, differently shaped chassis.

NEC released its final variation of the PC Engine Duo on June 25, 1994. The PC Engine Duo-RX (PCエンジンDuo-RX, Pī Shī Enjin Duo Āru Ekkusu) has a bluer chassis, and was bundled with a six-button gamepad.

In a game console comparison published in May 1995, Famicom Tsūshin rated the PC Engine Duo 22 out of 40.^[1]

North America

TTI released the TurboDuo to consumers in North America in October 1992, at a retail price of US$299.99. The price was, in part, a consequence of the relatively high cost of CD-ROM drive manufacturing.

Since TTI understood that the price was too high for many people in their target market, they included a booklet of coupons for TurboDuo games and accessories, plus several pack-in games on two CD-ROMs: Ys Book I & II (1990) and a SuperCD compilation of four of Hudson Soft's more popular TurboGrafx-16 titles: Bonk's Adventure (1989), Bonk's Revenge (1991), Gate of Thunder (1992), and Bomberman (1983). (Bomberman was hidden in an Easter egg.) The package also included one TurboChip game: Dungeon Explorer (Hudson Soft 1989).

Later, TTI replaced Dungeon Explorer with one of a variety of TurboChip titles, such as Ninja Spirit (Irem 1988) and Final Lap Twin (Namco 1989).

With the release of the TurboDuo, TTI reduced the retail price of the TurboGrafx-CD peripheral for the TurboGrafx-16 to $150.00, and began marketing the Super System Card, which enabled the TurboGrafx-CD to play the new SuperCD games. The Super System Card is preprogrammed with the updated v3.0 BIOS, and increases the TurboGrafx-16's RAM by 192 kilobytes. The TurboGrafx-CD requires the updated BIOS to read SuperCD discs, and the additional RAM to run the software capably. The Super System Card retailed for US$65 or, when bundled with the TurboDuo's SuperCD compilation disc, US$95.

For the TurboDuo marketing campaign, TTI used a character called Johnny Turbo.^[2] In 1998, Jonathan J. Burtenshaw of GameSpy described the advertising campaign as "petty" and "overly confrontational," and conjectured that the campaign hurt TurboDuo sales.^[3]

Technical specification

The Japanese PC Engine Duo

CPU

The Hudson Soft HuC6280 is a modified 65C02 with an effective clock rate of 1.79 or 7.16 MHz (switchable by software). The integrated components of this 8-bit processor include a timer, general-purpose I/O port, and bankswitching hardware (which drives a 21-bit external address bus from a 6502-compatible 16-bit address bus). It is capable of block transfer instructions, as well as dedicated move instructions for communicating with the TurboDuo's video display controller, the HuC6270A.

Video processing

• One 16-bit HuC6260 video color encoder (VCE)
• One 16-bit HuC6270A video display controller (VDC). Like the TMS99xx family of video display processors, it has port-based I/O.

Display resolution

• Horizontal lines: Maximum of 512, programmable in 8-pixel increments
• Vertical lines: Maximum of 240, programmable in 8-pixel increments

Nearly all TurboGrafx-16 games use 256×224. Sherlock Holmes Consulting Detective did use 512×224.

The TurboDuo used a different controller port, so use of older controller and accessories required an adapter.

Color

• Color depth: 9-bit
• 512-color palette (maximum of 481 colors on-screen: 241 for background tiles, 240 for sprite)s
• Up to 32 palettes (16 for background tiles, 16 for sprites)
• Up to 16 colors per palette

Sprites

• Sizes: 16×16, 16×32, 32×16, 32×32, 32×64
• Simultaneously displayable: 64 (maximum of 8–16 per line, depending on sprite width)
• Each sprite can use up to 15 unique colors (one color must be reserved as transparent) via one of the 16 available sprite palettes.
• The HuC6270A VDC can display one sprite layer. Sprites could be placed either in front of or behind background tiles.

Tiles

Each 8×8-pixel 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. The HuC6270A VDC can display one background layer.

Memory

• Work RAM: 8 KB
• Video RAM: 64 KB
• Additional 192 KB of built in Memory (System 3.0)

Sound

• Six PSG audio channels, programmable through the CPU
• One ADPCM channel
• Compact Disc Digital Audio

Software media

• TurboChip (called HuCARD in Japan), a thin, card-like ROM cartridge. Published games consumed up to 20 Mb (2.5 MB).
• CD-ROM

See also

• List of PC Engine emulators
• List of TurboGrafx-16 games
• List of TurboGrafx-CD and PC Engine-CD games

References

External links

• PC-Engine technical documentation for programmers at MagicEngine.com
• Frozen Utopia, a website for PC-Engine game developers