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 Super CD 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 Super CD games. The Super System Card is programmed 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 Super CD 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 Super CD compilation disc, US$95. For the TurboDuo marketing campaign, TTI used a character called "Johnny Turbo". In 1998, Jonathan J. Burtenshaw of GameSpy described the advertising campaign as "petty" and "overly confrontational," and conjectured that the campaign hurt TurboDuo sales. Technical specification 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 Color Color depth: 9-bit 512-color palette (maximum of 481 colors on-screen: 241 for background tiles, 240 for sprites) Up to 32 palettes (16 for background tiles, 16 for sprites) Up to 16 colors per palette (15 colors