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 Japan in May 1991.

Hardware

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, 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, which 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

History

The Teradrive was announced in Japan towards the end of 1990.

The Teradrive opted to use Sonic the Hedgehog as a way to demonstrate its ability to run Mega Drive software. However, at launch it was not possible to play Sonic on the Teradrive, as the game was not released in Japan until the end of July. This also means marketing material had to resort to showing prototype verisons 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.

Magazine articles

Promotional material

Photo gallery

Keyboard

Mouse

Driver disk

DOS disk

Merchandise

Telephone card

Physical scans

Teradrive, JP (Model 1)

Teradrive, JP (Model 2) Cover

Teradrive, JP (Model 3) Cover

Teradrive, JP (HTR-2200 monitor)

Teradrive, JP (HTR-2300A mouse)

References



