The Sega Genesis Model 1 — known as the Mega Drive outside North America — debuted in Japan on October 29, 1988, then in the US in August 1989. The Model 1 chassis (often nicknamed the 'High Definition Graphics' or 'Altered Beast' revision) carries Sega's familiar 8-pin DIN A/V port out the back, an RF antenna output, and a front-panel 3.5mm headphone jack with hardware volume slider — the only Genesis revision that put true stereo audio on the front. Two DE-9 controller ports sit up front, with the side expansion edge connector serving the Sega CD Model 1 and a vestigial 9-pin EXT port on the rear of the earliest units that was never commercially used.
Sega’s 16-bit Mega Drive — Model 1 with 8-pin DIN A/V, RF out, front 3.5mm headphone jack with stereo volume slider, and two DE-9 controller ports.
Device Information
- Manufacturer
- Sega
- Release Year
- 1988
- Model Number
- MK-1601 (US) / HAA-2510 (JP)
- Category
- Gaming Console
Available Ports
| Connector | Quantity | Label | Notes |
|---|---|---|---|
| Sega 8-pin DIN A/V (Master System / Genesis Model 1) | 1 | AV OUT (rear) | Same 8-pin DIN as the Master System. Carries composite video + mono audio at the connector; stereo is only available via the front headphone jack on Model 1. |
| RF Antenna Input (Coaxial) | 1 | RF OUT (rear) | Connects to a TV's antenna input via the supplied RF switch box. |
| 3.5mm TRS (Stereo Audio) | 1 | Headphone (front) | Front-panel stereo headphone jack with hardware volume slider. Unique to Model 1 — the Model 2 dropped it in favour of stereo at the AV port. Doubles as the source for the Sega CD audio mixing cable. |
| DE-9 (Atari / Sega Joystick Port) | 2 | Controller 1 / 2 (front) | Atari-style 9-pin D-sub controller ports. Compatible with Master System pads and 3-button / 6-button Genesis pads. |
Notes & Compatibility
Rear: 8-pin DIN A/V, RF antenna out, DC barrel power inlet (not modeled). Earliest Model 1s also have a rear 9-pin EXT port (same pinout as a controller port but female) — removed on later Model 1 revisions and never used commercially. Front: 3.5mm stereo headphone jack with hardware volume slider, two DE-9 controller ports. Right side: edge expansion connector for the Sega CD Model 1 (not modeled — console-to-console docking edge connector). Top: cartridge slot (not modeled).
