From Sega Retro

Teradrive logo.png
Manufacturer: IBM, Sega
Release Date RRP Code
Sega Mega Drive
¥148,000 (152,440)148,000e[1] HTR-2000
Sega Mega Drive
(Model 2)
¥188,000 (193,640)188,000e[1] HTR-2001
Sega Mega Drive
(Model 3)
¥248,000 (255,440)248,000e[1] HTR-2002
Sega Mega Drive

The Teradrive (テラドライブ) is a hybrid computer system developed by Sega and IBM containing both an IBM PC and Sega Mega Drive. It was released exclusively in Asia in May 1991.


The TradeMark Security System screen used by the Teradrive.

The Teradrive was designed to fullfil two roles, being a fully fledged IBM PC AT-class PC system also capable of running Mega Drive games through standard cartridges. Three models were made available with different RAM, floppy disk and hard drive configurations (for the PC side), alongside a full keyboard, two-button mouse, full colour monitor (all in black plastic) and range of specialised software. Like other IBM compatibles, the system can be modified and expanded by users if necessary.

The Teradrive was always envisioned as a low cost machine for the home, which is reflected in its choice to use IBM's PS/2 Model 30 286 as a base for the PC side (itself one of the lower cost variants of the PS/2 family). By 1991, more advanced 386 and 486 computers (including those sold by IBM) were becoming more common, and in some cases were actually cheaper than any of the three Teradrive configurations. Sega instead emphasised the fact the machine had two processors (though technically it has three), with the Mega Drive's 68000 playing a role in advertising.

As a Mega Drive, it is identical to a standard NTSC-J console and uses its own version of the TradeMark Security System, but lacks any support for the Sega Mega-CD or Sega 32X. While the Mega-CD was not announced until after the Teradrive's launch, support for it was planned, with Sega creating at least two prototype Mega-CD units around the Teradrive's (otherwise unused) expansion port. Poor sales of the Teradrive meant development of this add-on was cancelled before designs left the prototype stage.

The Teradrive also allows some degree of interaction between the PC and Mega Drive hardware. The only known software to make use of this is Puzzle Construction and The Manhole, the former was included with the Teradrive. Exactly how the x86 code communicates with the Mega Drive hardware, and the limits of what is possible through this interface, are currently unknown. The Mega Drive's video signal can be passed to an external monitor, allowing for both the PC and Mega Drive portions to be used simultaneously.

Teradrives have a unique BIOS and menu system, however all shipped with IBM DOS J4.0/V and is expected to run all compatible software. Windows 3.0 was also advertised as being compatible.

Technical specifications

For Mega Drive specifications, see Sega Mega Drive/Technical specifications.

The Teradrive came in three different models with the main differences being RAM, storage, and price, aptly named Models 1-through-3[2].

All models (PC side)

  • Processor: 10MHz Intel 80286
  • Maximum supported RAM: 2.5MB
  • Graphics: VGA
    • 640x480 (262144 colors/16 on-screen)
    • 320x200 (262144 colors/256 on-screen)
  • Sound: PC speaker
  • I/O ports: VGA, parallel, 1x RS232 serial, 2x PS/2, 2x Mega Drive controller ports, unused Mega-CD expansion, 15-pin RGB connector

Model 1

  • RAM: 640KB
  • Floppy disk drive: 1x 3½-inch 2HD
  • Price: ¥148,000

Model 2

  • RAM: 1MB
  • Floppy disk drive: 2x 3½-inch 2HD
  • Price: ¥188,000

Model 3

  • RAM: 2.5MB
  • Floppy disk drive: 1x 3½-inch 2HD
  • Storage: 30MB HDD (with DOS/V already installed)
  • Price: ¥248,000


The Teradrive was developed jointly by Sega and IBM. During development, the latter codenamed the hardware "Spica", following its naming scheme based on stars. Sega were influenced by this, creating their planet codenames scheme and choosing to initially call it "Terra", alternate name for Earth. However, the company discovered at the very last minute that the name had already been trademarked, instead opting for Teradrive based on the Mega –> Giga –> Tera logic.

Following its last minute renaming, the Teradrive was announced publicly in Japan towards the end of 1990. Sega opted to use Sonic the Hedgehog as a flagship means to demonstrate its ability to run Mega Drive software. However, at launch it was ultimately not possible to play Sonic on the Teradrive, as the game was not released in Japan until the end of July. This also meant that all marketing material had to resort to showing prototype versions of the game.

While the Teradrive was never sold outside of Japan, a similar Mega Drive/PC hybrid exists as the Mega PC by Amstrad. Released in 1993 in the United Kingdom, the Mega PC is more capable on the PC side, but similarly to the Teradrive, was a budget machine sold at a non-budget price. It also lacks any interaction between the Mega Drive and PC hardware, unlike the Teradrive, and is not thought to have had much input from Sega.


Production credits

Japanese version

Developer mentions[3][4][5]

Magazine articles

Main article: Teradrive/Magazine articles.

Promotional material

Main article: Teradrive/Promotional material.


Main article: Teradrive/Merchandise.

Photo gallery

Physical scans

Teradrive, JP (Model 1)

Teradrive, JP (Model 2)
TeradriveModel2 MD JP Box Front.jpg
Teradrive, JP (Model 3)
Teradrive3 MD JP Box Front.jpg
Teradrive, JP (HTR-2200 monitor)

Teradrive, JP (HTR-2300A mouse)

Teradrive, AS

External links


Sega Mega Drive
Topics Technical specifications (Hardware comparison) | History | List of games | Magazine articles | Promotional material | Merchandise | Cartridges | TradeMark Security System
Hardware Japan | North America | Western Europe | Eastern Europe | South America | Asia | South Korea | Australasia | Africa
EZ Games | LaserActive | Mega Jet | Mega PC | Mega Play | Mega-Tech System | Nomad | Teradrive | Mega Drive Mini | Mega Drive Mini 2
New Mega Drive | Tianli VCD/DVD Players | "Consoles on a chip" | Licensed clones (Magic 2 | Mega Game II | Power Pegasus | Super Bitman)
Unlicensed clones
Add-ons Game Box | Power Base Converter | Mega-CD | 32X (Mega-CD 32X) | Mega Modem | Demo System DS-16
Cases Sega Genesis Nomad Carrying Case | System Carry Case
Controllers Control Pad | Six Button Control Pad | 6 Button Arcade Pad | Arcade Power Stick 6B | Konami Justifier | MK-1470
Action Chair | Activator | Arcade Power Stick | Keyboard | MegaFire | Mouse | Mega Stick | Menacer | Remote Arcade System | Ten Key Pad | Third Party Controllers
Accessories 4 Way Play | Cleaning System | Control Pad Extension Cord | Genesis Speakers | Headset | HeartBeat Catalyst | Microphone | Region converter cartridges | Mega Terminal | Nomad PowerBack | RF Unit (Mega Drive 2) | SCART Cable (Mega Drive 2) | Stereo Audio Video Cable | Team Player | Video Monitor Cable | Third Party Accessories
Network services Sega Channel | Sega Game Toshokan | Mega Anser | Mega Net | TeleBradesco Residência | XB∀ND
Development tools ERX 308P | ERX 318P | Sprobe | SNASM68K | SNASM2 (Mega Drive) | SNASM2 (32X) | PSY-Q Development System (Mega Drive) | PSY-Q Development System (32X) | 32X CartDev | Sega Mars Development Aid System | Sega 32X Development Target
Unreleased Edge 16 | Floppy Disk Drive | Mega Play 1010 | Sega VR | Teleplay System | Video Jukebox