The overall design is not unlike the original version of the Game Boy Advance. The GP32 is based on a 133 MHz ARM CPU and 8 MB of RAM. Unlike other hand held gaming systems, which tend to be proprietary cartridge-based, the GP32 uses SmartMedia cards (SMC) for storing programs and data, making it accessible for amateur developers as no further development hardware is required.
The console has a four-way mini-joystick controller, two main buttons ('A' and 'B'), two shoulder buttons on each side of the SMC slot ('L' and 'R') and two other menu buttons on each side of the screen ('SELECT' and 'START'), made from a softer, translucent rubber. The console also has a USB 1.1 port for connection with a host computer, a serial expansion port, a 3.3 V power adapter input, a headphone connector and a rear compartment which holds two AA sized batteries.
Source: Wikipedia, "GP32", available under the CC-BY-SA License.