The TurboExpress was a handheld video game console, released by NEC in 1990. It was essentially a portable version of the Turbografx-16/PC-Engine home console that came 2 to 3 years earlier. It was known as the PC Engine GT (Game Tank) in Japan.
As part of the fourth generation of gaming, the TurboExpress primarily competed with Nintendo's Game Boy, Sega's Game Gear, and the Atari Lynx. However, with just a mere 1.5 million units sold, behind its main competitors, the TurboExpress failed to gain significant sales or market share.
It was the most advanced handheld of its time and could play all the TurboGrafx-16's HuCard games. It had a 66 mm (2.6 in.) LCD screen, the same as the original Game Boy, and could display 64 sprites at once, 16 per scanline, in up to 481 colors from a palette of 512. It had 8 kilobytes of RAM. The Turbo ran its HuC6280 CPU at 1.79 or 7.16 MHz.
The following diagram comes from pcenginefx.com.