From Sega Retro
The Arcade Portable is a handheld Sega Mega Drive console on a chip manufactured by AtGames. It was the second handheld to be produced by AtGames, following the Arcade Gamer Portable, and was bettered by the Arcade Ultimate.
Like many of AtGames' products, the true name for this handheld is not known. AtGames' website calls it the Arcade Portable, but the device was renamed by various distributors. Packaging calls it the Mega Drive Portable Video Game Player. The system was manufactured by AtGames who distributed across Asia. Blaze Europe distributed across Europe and Tectoy brought it to Brazil.
The device has a built in 2.4-inch LCD screen, with the option for TV output, and runs Mega Drive games through SD cards. As well as this, the system comes bundled with a number of built-in games, which differ between distributors. The system is incompatible with traditional Mega Drive cartridges and runs on three AAA batteries.
Problems with the Unit
It seems that the PSG chip in the unit is tuned incorrectly, and all sound produced by the PSG is 7 semitones too low. While this isn't noticeable on most music in games, it does occasionally become obvious, such as Knuckles' theme in Sonic and Knuckles.
While TV output for the Hong Kong device works fine, on the UK device they made a fatal error. It has been adjusted to run at 50 Hz, but it still outputs an NTSC composite signal, causing it to be black and white on UK TVs that do not support the hybrid NTSC-50 standard.
TecToy and AtGames Versions Games
Blaze Version Games
Qjimbo put together this short guide on how to take the device apart, to get a look at the components inside.
Inside there are two chips. The large one with a separate PCB is the ROM chip, and the one under the black blob is the CPU.