AtGames Portable Mega Drive
From Sonic Retro
Contents |
Overview
This portable Mega Drive unit, designed by Digital Media Cartridge Ltd, is a portable mega drive, which uses a "Megadrive on a chip" to run various built in games. It is distributed in China by Sega's official distributor in the region, AtGames.
Games on the Hong Kong release
- Alex Kidd and the Enchanted Castle
- Alien Storm
- Altered Beast
- Arrow Flash
- Columns III
- Crack Down
- Decap Attack
- Dr. Robotnik's Mean Bean Machine
- E-Swat: City Under Scope
- Ecco the Dolphin
- Ecco Jr.
- Flicky
- Gain Ground
- Golden Axe
- Jewel Master
- Kid Chameleon
- Ristar
- Shadow Dancer
- Sonic & Knuckles
- The Revenge of Shinobi II
Games on the UK release
- Alex Kidd and the Enchanted Castle
- Alien Storm
- Altered Beast
- Arrow Flash
- Columns III
- Crack Down
- Decapattack
- Dr. Robotnik's Mean Bean Machine
- E-Swat: City Under Scope
- Ecco the Dolphin
- Ecco Jr.
- Shinobi III
- Flicky
- Gain Ground
- Golden Axe
- Jewel Master
- Kidd Chameleon
- Sonic Spinball
- Shadow Dancer: The Secret of Shinobi
- Sonic & Knuckles
The most notable difference is the lack of Ristar in the UK release.
Problems with the Unit
PSG sound
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 noticable on most music in games, it does occasionally become obvious, such as Knuckles' theme in Sonic and Knuckles.
TV Output
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 50hz, 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.
Disassembly Guide
Qjimbo put together this short guide on how to take the device apart, to get a look at the components inside.
 Step 1: Remove the batteries and every screw on the back. 5 screws in total, the battery panel screw and a screw on each corner. |
 Step 2: Prize open the the case. I found that around the volume control is a good place. |
 Step 3: Work your way around the edges. There are 2 clips on each side. |
 Step 4: Once you have undone all the clips, pull apart the case. The area around the battery compatment is stuck with sticky pads, but it is fairly easy to still pull it apart. |
 Step 5: Remove the 2 small screws each side of the main circuit board. There are actually 4 screw holes so some people may have 4 screws to remove. |
 Step 6: This part is fiddly, but carefully pull the circuit board out of the case. Again, around the volume control seems a good place. |
 Step 7: You're done! |
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. Research into whether a custom ROM could somehow be run on this device is still taking place.
| Sega Mega Drive Hardware | |
| Mega Drive and Variations | Mega Drive | Genesis 3 | Mega Jet | Nomad | Teradrive |
|---|---|
| Mega CD and Variations | Mega CD | CDX | X'eye | Aiwa Mega CD |
| Other Add-ons | 32X | Power Base Converter | Super Magic Drive | Tototek MD-Pro |
| Special Game Controllers | Mega Mouse | Menacer | Activator |
| Online Services | Meganet | Channel | XB∀ND |
| Misc. Hardware | Sega Mega Anser | MegaPlay | MegaTech | Game Genie |
| Embedded Units | Legends Series | AtGames Twin Pad Player | AtGames Portable Mega Drive |
