The TurboDuo is a fourth-generation video game console developed by NEC Home Electronics and Hudson Soft for the North American market and is the North American version of the Japanese PC Engine Duo game console, which was released in September 1991, unlike TurboDuo, which was released in October 1992.
This console combines the capabilities of the TurboGrafx-16, Super System Card, and the TurboGrafx-CD in one package, redesigned with an updated BIOS and 192 KB of additional RAM. This means that TurboDuo is capable of playing all games released for Turbografx, as well as CDs. So, that makes it a retro console with a surprisingly big gaming library. There are 94 Turbochip games released in North America and 417 CD games released in both regions, Japan and North America.
Moving on to the technical assets, 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. It should be noted that controllers are not compatible between the Turbografx and TurboDuo, as the slots are shaped differently. However, PC Engine controllers are the same style and will also work with the console.
Basically, TurboDuo is a better and fuller version of Turbografx which also includes stereo output via RCA jacks, so even chip games will look and sound better here than on a basic Turbografx system.